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20 minutes ago, Bfg said:

Ah the position or size of the splines. Brilliant. I'm hoping to swap out the whole half-shaft so that ought not be an issue.   

I do, very much, appreciate your prompt reply as I've just raised the car on stands and am just about to tackle it.

Pete.

No Ive seen some with a screw cap like the prop and also a turnkey too.

Stuart.

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Pete - DON'T give up with owning a TR - there are other cars out there - just put the word out on here and elsewhere and I'm sure something will come up Chin up  Cheers Rich

Or these people? http://www.leacyclassics.com/parts/classicmini/engine-components/2k7440.html Roger

. Carrying on from TR4 -v- Tr4A engine, and my purchasing a 'spare'  < here >  ..so that I might get on and have an engine ready by the time the Chance is actually bought and shipped,  we h

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Thanks Stuart.   Half-shaft has now been swapped out..

P1390616s.thumb.JPG.10d97af2399712f94ee93e9efbe19767.JPG

^ the original from this car (top) and one I bought hoping it was OK below.  :huh: fingers crossed.

Rear springs now swapped out for those that were originally on the car.  

Five hours later, as I had to first swap the wheels studs over, and then had issues with one of the six studs holding the hub to the trailing-arm being loose / a stripped thread, the sliding handbrake mechanisms having no lubrication, and then again the handbrake cable mounting on the top of the trailing-arm being loose, no washer under it, and a binding nut.   It's all back together now but for doing the wheel bearing nut up.  Not turned a wheel yet so don't know what the ride height like is yet. 

Pete

 

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12 hours ago, Bfg said:

Thanks Stuart.   Half-shaft has now been swapped out..

P1390616s.thumb.JPG.10d97af2399712f94ee93e9efbe19767.JPG

^ the original from this car (top) and one I bought hoping it was OK below.  :huh: fingers crossed.

Rear springs now swapped out for those that were originally on the car.  

Five hours later, as I had to first swap the wheels studs over, and then had issues with one of the six studs holding the hub to the trailing-arm being loose / a stripped thread, the sliding handbrake mechanisms having no lubrication, and then again the handbrake cable mounting on the top of the trailing-arm being loose, no washer under it, and a binding nut.   It's all back together now but for doing the wheel bearing nut up.  Not turned a wheel yet so don't know what the ride height like is yet. 

Pete

 

Do you know the provenance of the s/hand shaft? I`m wondering why anyone would bother undoing the hub nut unless it was a failed attempt to remove the hub in which case it may have already been over strained on the shaft. Personally I wouldnt have touched it with a barge pole. Not nice to have a hub shaft part company.

Stuart.

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On 9/16/2021 at 9:36 AM, stuart said:

Do you know the provenance of the s/hand shaft? I`m wondering why anyone would bother undoing the hub nut unless it was a failed attempt to remove the hub in which case it may have already been over strained on the shaft. Personally I wouldn't have touched it with a barge pole. Not nice to have a hub shaft part company.

Stuart.

Alas, no I don't.  

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Yesterday Mathew (Puma-powered Spitfire ..from the TSSC ), very kindly drove down from Norfolk to give us a hand. Two minds looking at the same problems from different experience-perspectives, as well as another pair of hands when measuring toe-in, camber and tracking, was very useful and he's good company and an interesting chap to hang out with.   Mathew also has toe-in checking equipment which gave definitive, if at some times a little confusing, data.    I might add that the confusion was mostly on my part because I'd never used such no-smoke-&-one-mirror tricks before.  I'm old school and so still use a length of cord along with a tape measure and a spirit level. 

First thing though was to do the final task of swapping the half shaft out and replacing rear the suspension springs for those that came off the car.  I'd assessed that they were of the same spec as the replacement ones, but I figured the replacements were perhaps less 'tired' than the originals ..so with the old springs back in the car - she might settle lower.  That final task was to tighten the central hub-assembly nut up to the prescribed 100-110 ft lb.  which with my background in old bikes rather than cars, leaves me a slight disadvantage. To me (having never had a hub apart to see the bearing assembly & inner workings) that big nut appears to be a wheel-bearing nut, which with old cars I thought was "pinched-up tight and backed-off by one flat of the nut"  ..then put the split-pin in and it's good to go. 

However, the Triumph workshop manual, under torque settings (at the very front a manual with no index) it says "Rear Hub Assembly ... 5/8" x 20 UNF stub axle ... 100 to 110 ft. lb."   In part this information is copied across to the Haynes manual but their semantics confuse things by describing it as "Inner driving flange to inner axle (IRS), which doesn't tie in with either my jargon nor their exploded diagram.  Anyways up, the figures agree and so 110 ft.lb. is what it was done up to.  

We then went for a few miles test drive around Suffolk's unclassified and b-roads, pushing the car into corners as fast as other road users would allow.  Aside from a quick stop to lift the top off the carb's float bowl to clear its needle from sticking again, the handling felt much better.  In fact the car in general sounded and felt almost passable, albeit with rather light steering and a tendency to over-steer in faster tight corners where subsidence made the road surface uneven.  However, when we got back and measured the ride height (having rolled the car forward and onto a level packing (plywood under one wheel) - the car is sitting no lower with these springs than those M&T fitted.  It also remains higher on the passenger side than the driver's.   In summary, I might only attribute the better feel of the car to having two people in it rather than just myself.  

Mathew then got his laser and mirror toe-in checking device out and we checked the rear axles  . . .

Toe-in of the rear wheels and Tracking..

P1390627s.JPG.03c8894a61c5cefa781c954a74023dcb.JPG   P1390628s.JPG.da285c8d2f1810089e057a2b62c8fcc5.JPG 

^ Having set up the mirror to the LHS rear wheel rim, the laser's red dot is reflected back to its gauge and centred ..as a datum to compare with. The laser is then left untouched as the mirror is moved to rest against the rim of the RHS rear wheel.  The reflected red dot now tells us what the difference in angle is.  As you can see in the second photo., that was recorded as about 13 minutes of a degree (ie., about an eigth of a degree toe out).   The workshop manual tells us that the axles (front and rear) should be set zero (neutral) to 1/16" toe in.  I could convert from 1/16" to degrees but for the time being we'll leave it ..as to adjust the toe-out to toe-in would involve re-shimming inbetween one trailing arm bracket and the chassis rail.  And Mathew reckoned that even removing just one shim would result in too much adjustment.. He has a Triumph 2000 with much the same IRS suspension as this, so I'm happy to take his word for it.  In any case although the device highlights this tiny inaccuracy, it doesn't tell us which (left or right) trailing arms is out of alignment.

Me, well I'm old school.. and I had a piece of cord to work with. . .

P1390629s.thumb.JPG.d212d3d145aaa8dedfa637e1904e20a0.JPG

^ with the cord tied to the exhaust tail pipe ('cause I'm right-sophisticated with my engineering set-ups) and pulled taught around all four tyres (the cord clearing the sills and otherwise pretty close to being parallel to the ground) we could then use a tape measure or rule to measure front and back dimensions between each wheel rim and the cord).  Those dimensions were of course in inches or mm, and it's intuitive to see which wheel was pointing where.   NOTE : we did allow for the difference in width of front and rear axle tracks, with 5mm packers under the cord on each rear tyre.

The rear wheels were very close (measured as about 2 - 3.5mm out of track) but the front wheel tracking ..which I was told by Mark had been done by a commercial tyre centre in Wolverhampton, was 10 - 12mm toe-out.  Oops !  It is meant to be 0 - 1/16" toe-in.  

So we went for lunch  

Thereafter we adjusted that, at the steering rack's tie-rods (..either end to try and keep the steering-wheel straight).  For this task - the laser & mirror was helpful and very much more precise than the cord and tape measure.  Accordingly, I've now set them to about 3-5 minutes toe in, but I also accept that's a temporary setting, as there's play in the steering rack itself. 

At the local TSSC evening meet-up a member kindly flagged this, as most likely being the rack's inner ball joint.  Again this is something that I would have thought M&T's mechanic should have noted and advised on ..perhaps asking if I wanted it exchanged or refurbished while the body was off.   It's noticeable enough, as is a wobbly rear wheel bearing, that they otherwise ought to have been flagged by the MOT.   Anyway, they're now just other items on my job list.

Checking the cord, now with the front wheels in line, revealed that the rear track was so close to being correct as to be of no concern. The cord, previously held out of true by the front wheels - corrupted our previous measurements at the rear.  Measured again, the rear wheel rim to cord dimensions were so close, on both sides as to be negligible, and indeed (if I recall correctly indicated) 1.5mm toe in.   I'll check that again because the recollection contradicts the laser readings, but 1.5mm, in or out, on a 15" rear wheel is pretty close ..and it may yet adjust when the ride height and the wheel's positive camber are corrected.    

Our second test drive confirmed that the steering was very much better now, with a little feel (rather than being a little too light), and so very much better feel in corners, in particular left-handers for some reason.  I still felt that the car was rolling over its suspension and skittish when pushed (or over pushed !) ..but still we had achieved a noticeable improvement for very little effort.   I leveled the floor by the patio before driving straight in (no reversing to wind-up the suspension) and we checked the ride height again and also looked into the positive (leaning out at their top) camber of the rear wheels.

Ride Height .   The ride height measured (wheel centre to underside of wheel-arch rim) as 405mm on the RHS, and 425mm on the LHS.  Checking against a spirit level across the car, we've determined that the LHS wheel-arch is 10mm higher than the other (down to body tub, wing shape or where it's fitted), so the passenger side will look higher by that amount.  The body is sitting some 8-10mm higher on this chassis, probably thanks to having new rubber body-mount pads inbetween the two.  And the poly-bush spring collars are each 3 - 5mm thicker than the old rubber ones and so, due to the geometry of spring to hub distance, would raise the rear suspension by 6 to 10mm for each collar.  x2 collars for each spring = 12 to 20mm increase in ride height.  I'm not sure I can do much about that, but to fit shorter / lowered springs.   But I'll wait to see how correcting the camber changes things.

Camber  Unfortunately Mathew's camber checking device wouldn't work on this car, because there is no flat surface on the wheels for the device to fit it against.  Apparently it's often set against the flat of a brake disk.  So back to old-school ways of doing things.. ie., a spirit level set vertically from the ground and resting / steadied against the wheel arch. From this straight edge datum its easy enough to measuring the distances to the wheel rim. 

The measurement itself is meaningless (because of wheel arch brow dimension is not accurate) but the difference in dimension between that taken at the top and bottom of the wheel rim - tells us the camber.  That is measured in mm but is easy to convert to angle when you know the diameter of the wheel rim (395mm in the case of these 15" wheels).  Each wheel measured 10mm or thereabouts of positive camber.  That equates to 1.45 deg positive camber when it should be +/-  0 to 0.5 of a degree.   Only with my 105kg bulk sitting on the rear wing / on the rear light did we get close to getting the suspension height change to adjust the wheel camber to close to being zero.    

At speed around a corner I'd fall off   so I'll next need to adjust the camber by altering the trailing arm brackets. I'm going to try reversing which way around they are fitted onto the chassis rail. 

That's it. It was time for a quick cuppa tea, and for Mathew to look at some Caterham seats I have, before he headed for home.  

I know what's got to be done. It's a little frustrating that I'm having to do it, but I'm at least of a calm piece of mind to get one with it, possibly over the weekend.

Big Thanks to Mathew for his help, patience, amicable nature and positive motivation. 

He's taking an unscheduled break from jobs right now, and I wish him a speedy recovery. 

Pete.

 

 

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On 9/15/2021 at 9:55 PM, Bfg said:

Thanks Stuart.   Half-shaft has now been swapped out..

P1390616s.thumb.JPG.10d97af2399712f94ee93e9efbe19767.JPG

^ the original from this car (top) and one I bought hoping it was OK below.  :huh: fingers crossed.

Rear springs now swapped out for those that were originally on the car.  

Five hours later, as I had to first swap the wheels studs over, and then had issues with one of the six studs holding the hub to the trailing-arm being loose / a stripped thread, the sliding handbrake mechanisms having no lubrication, and then again the handbrake cable mounting on the top of the trailing-arm being loose, no washer under it, and a binding nut.   It's all back together now but for doing the wheel bearing nut up.  Not turned a wheel yet so don't know what the ride height like is yet. 

Pete

 

They look like coming fresh from the hay....:ph34r:

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On 9/17/2021 at 4:44 PM, Bfg said:

Yesterday Mathew (Puma-powered Spitfire ..from the TSSC ), very kindly drove down from Norfolk to give us a hand. Two minds looking at the same problems from different experience-perspectives, as well as another pair of hands when measuring toe-in, camber and tracking, was very useful and he's good company and an interesting chap to hang out with.   Mathew also has toe-in checking equipment which gave definitive, if at some times a little confusing, data.    I might add that the confusion was mostly on my part because I'd never used such no-smoke-&-one-mirror tricks before.  I'm old school and so still use a length of cord along with a tape measure and a spirit level. 

First thing though was to do the final task of swapping the half shaft out and replacing rear the suspension springs for those that came off the car.  I'd assessed that they were of the same spec as the replacement ones, but I figured the replacements were perhaps less 'tired' than the originals ..so with the old springs back in the car - she might settle lower.  That final task was to tighten the central hub-assembly nut up to the prescribed 100-110 ft lb.  which with my background in old bikes rather than cars, leaves me a slight disadvantage. To me (having never had a hub apart to see the bearing assembly & inner workings) that big nut appears to be a wheel-bearing nut, which with old cars I thought was "pinched-up tight and backed-off by one flat of the nut"  ..then put the split-pin in and it's good to go. 

However, the Triumph workshop manual, under torque settings (at the very front a manual with no index) it says "Rear Hub Assembly ... 5/8" x 20 UNF stub axle ... 100 to 110 ft. lb."   In part this information is copied across to the Haynes manual but their semantics confuse things by describing it as "Inner driving flange to inner axle (IRS), which doesn't tie in with either my jargon nor their exploded diagram.  Anyways up, the figures agree and so 110 ft.lb. is what it was done up to.  

We then went for a few miles test drive around Suffolk's unclassified and b-roads, pushing the car into corners as fast as other road users would allow.  Aside from a quick stop to lift the top off the carb's float bowl to clear its needle from sticking again, the handling felt much better.  In fact the car in general sounded and felt almost passable, albeit with rather light steering and a tendency to over-steer in faster tight corners where subsidence made the road surface uneven.  However, when we got back and measured the ride height (having rolled the car forward and onto a level packing (plywood under one wheel) - the car is sitting no lower with these springs than those M&T fitted.  It also remains higher on the passenger side than the driver's.   In summary, I might only attribute the better feel of the car to having two people in it rather than just myself.  

Mathew then got his laser and mirror toe-in checking device out and we checked the rear axles  . . .

Toe-in of the rear wheels and Tracking..

P1390627s.JPG.03c8894a61c5cefa781c954a74023dcb.JPG   P1390628s.JPG.da285c8d2f1810089e057a2b62c8fcc5.JPG 

^ Having set up the mirror to the LHS rear wheel rim, the laser's red dot is reflected back to its gauge and centred ..as a datum to compare with. The laser is then left untouched as the mirror is moved to rest against the rim of the RHS rear wheel.  The reflected red dot now tells us what the difference in angle is.  As you can see in the second photo., that was recorded as about 13 minutes of a degree (ie., about an eigth of a degree toe out).   The workshop manual tells us that the axles (front and rear) should be set zero (neutral) to 1/16" toe in.  I could convert from 1/16" to degrees but for the time being we'll leave it ..as to adjust the toe-out to toe-in would involve re-shimming inbetween one trailing arm bracket and the chassis rail.  And Mathew reckoned that even removing just one shim would result in too much adjustment.. He has a Triumph 2000 with much the same IRS suspension as this, so I'm happy to take his word for it.  In any case although the device highlights this tiny inaccuracy, it doesn't tell us which (left or right) trailing arms is out of alignment.

Me, well I'm old school.. and I had a piece of cord to work with. . .

P1390629s.thumb.JPG.d212d3d145aaa8dedfa637e1904e20a0.JPG

^ with the cord tied to the exhaust tail pipe ('cause I'm right-sophisticated with my engineering set-ups) and pulled taught around all four tyres (the cord clearing the sills and otherwise pretty close to being parallel to the ground) we could then use a tape measure or rule to measure front and back dimensions between each wheel rim and the cord).  Those dimensions were of course in inches or mm, and it's intuitive to see which wheel was pointing where.   NOTE : we did allow for the difference in width of front and rear axle tracks, with 5mm packers under the cord on each rear tyre.

The rear wheels were very close (measured as about 2 - 3.5mm out of track) but the front wheel tracking ..which I was told by Mark had been done by a commercial tyre centre in Wolverhampton, was 10 - 12mm toe-out.  Oops !  It is meant to be 0 - 1/16" toe-in.  

So we went for lunch  

Thereafter we adjusted that, at the steering rack's tie-rods (..either end to try and keep the steering-wheel straight).  For this task - the laser & mirror was helpful and very much more precise than the cord and tape measure.  Accordingly, I've now set them to about 3-5 minutes toe in, but I also accept that's a temporary setting, as there's play in the steering rack itself. 

At the local TSSC evening meet-up a member kindly flagged this, as most likely being the rack's inner ball joint.  Again this is something that I would have thought M&T's mechanic should have noted and advised on ..perhaps asking if I wanted it exchanged or refurbished while the body was off.   It's noticeable enough, as is a wobbly rear wheel bearing, that they otherwise ought to have been flagged by the MOT.   Anyway, they're now just other items on my job list.

Checking the cord, now with the front wheels in line, revealed that the rear track was so close to being correct as to be of no concern. The cord, previously held out of true by the front wheels - corrupted our previous measurements at the rear.  Measured again, the rear wheel rim to cord dimensions were so close, on both sides as to be negligible, and indeed (if I recall correctly indicated) 1.5mm toe in.   I'll check that again because the recollection contradicts the laser readings, but 1.5mm, in or out, on a 15" rear wheel is pretty close ..and it may yet adjust when the ride height and the wheel's positive camber are corrected.    

Our second test drive confirmed that the steering was very much better now, with a little feel (rather than being a little too light), and so very much better feel in corners, in particular left-handers for some reason.  I still felt that the car was rolling over its suspension and skittish when pushed (or over pushed !) ..but still we had achieved a noticeable improvement for very little effort.   I leveled the floor by the patio before driving straight in (no reversing to wind-up the suspension) and we checked the ride height again and also looked into the positive (leaning out at their top) camber of the rear wheels.

Ride Height .   The ride height measured (wheel centre to underside of wheel-arch rim) as 405mm on the RHS, and 425mm on the LHS.  Checking against a spirit level across the car, we've determined that the LHS wheel-arch is 10mm higher than the other (down to body tub, wing shape or where it's fitted), so the passenger side will look higher by that amount.  The body is sitting some 8-10mm higher on this chassis, probably thanks to having new rubber body-mount pads inbetween the two.  And the poly-bush spring collars are each 3 - 5mm thicker than the old rubber ones and so, due to the geometry of spring to hub distance, would raise the rear suspension by 6 to 10mm for each collar.  x2 collars for each spring = 12 to 20mm increase in ride height.  I'm not sure I can do much about that, but to fit shorter / lowered springs.   But I'll wait to see how correcting the camber changes things.

Camber  Unfortunately Mathew's camber checking device wouldn't work on this car, because there is no flat surface on the wheels for the device to fit it against.  Apparently it's often set against the flat of a brake disk.  So back to old-school ways of doing things.. ie., a spirit level set vertically from the ground and resting / steadied against the wheel arch. From this straight edge datum its easy enough to measuring the distances to the wheel rim. 

The measurement itself is meaningless (because of wheel arch brow dimension is not accurate) but the difference in dimension between that taken at the top and bottom of the wheel rim - tells us the camber.  That is measured in mm but is easy to convert to angle when you know the diameter of the wheel rim (395mm in the case of these 15" wheels).  Each wheel measured 10mm or thereabouts of positive camber.  That equates to 1.45 deg positive camber when it should be +/-  0 to 0.5 of a degree.   Only with my 105kg bulk sitting on the rear wing / on the rear light did we get close to getting the suspension height change to adjust the wheel camber to close to being zero.    

At speed around a corner I'd fall off   so I'll next need to adjust the camber by altering the trailing arm brackets. I'm going to try reversing which way around they are fitted onto the chassis rail. 

That's it. It was time for a quick cuppa tea, and for Mathew to look at some Caterham seats I have, before he headed for home.  

I know what's got to be done. It's a little frustrating that I'm having to do it, but I'm at least of a calm piece of mind to get one with it, possibly over the weekend.

Big Thanks to Mathew for his help, patience, amicable nature and positive motivation. 

He's taking an unscheduled break from jobs right now, and I wish him a speedy recovery. 

Pete.

 

 

As usual an in depth (and enjoyable read) write up regarding the lengths we owners go to to correct things with our cars. 

Since the initial work done, you seem a little more critical of the mechanical work done by the garage, but I guess when you invest a lot you expect a lot back, and some things seem irritating when you find them. 

I think you might be right that a set of lower springs might be your answer, don't forget if you've still to fit the bumpers, hood, spare wheel etc, they will add a bit of weight (I can't remember if your have fitted any of the above).

Looking forward to your next instalment. 

Gareth

 

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Thanks Gareth,

just as reference ; the car presently has its spare wheel in, usual tool kit, jack etc, 5 ltrs of water and 5 ltrs of oil in the boot (still from when I collected the car). Hood is on the car (it's a TR6 hood frame), and there's 3/4 tank of fuel.  Two standard seats are in, but no carpets or side trim panels, no bumpers or their irons.

Apologies if my recent posts appear harshly critical of M&T. That was not my intent, only to report what I've been doing. I'll watch my tone in future.  Again, I emphasis that my / their budget was limited, and this was not a full restoration.  Mark was very kind in numerous ways and many details done were beyond the remit.  So it's swings n' roundabouts to the jobs I'm now finding.  Overall I'm very pleased with the job M&T did with the chassis, but tbh feel that Mark was poorly let down on the final straight.

I trusted Mark to do, or have the work done properly ..and in turn he has to trust his workforce to do that ..even when he's not around to keep an eye on things.  I really like Mark and feel he's a very genuine guy, but I feel that he and therefore I have been let down by one or two in his team.  When I say 'done properly'  I not only mean reassembling parts correctly and torqued-up to spec., with pipes clipped securely, and things like the suspension set-up according to original spec., and panels straight and shutting quietly and easily without chafing  ..but I also mean conscientiously identifying potential issues, and advising me to ask if they might be addressed.. while access was easy.  But instead I've already found stripped-out threads, the fuel pipe kinked, fuel and brake pipes only held in place by a cable tie, exhaust clamps missing, and loose bolts. Whether on the prop-shaft, brake cable, or body mounts.. this shouldn't happen.  Likewise incorrect bolts and washers fitted, the chewed-up brake adjuster, coppaslip slapped over assembled parts rather than in them, no sign of greasing of common maintenance items like the trunnions and UJ's, a worn-out clonking half-shaft, a loose wheel bearing, a loose and clonking steering rack, the water tap leaking on the engine block, the gearbox now leaking oil ..even when the car is not driven, the gear-change spring being fitted upside down, shoddy wiring connections to the overdrive, and a host of other details.. are a poor show.  Some of which are potentially dangerous. 

Although I, and therefore M&T, were working to a tight budget ..I might add that above and beyond buying the chassis, having its mods done, and its swap - I paid a further two and half thousand pounds for additional work.  The best part of a thousand was in the gearbox and overdrive rebuild, and a similar figure was on having a single outer-sill panel replaced (and the NS door gaps better adjusted).  Tbh although the door gaps (when as seen from the side) are impressively much better ..that outer sill's fit is awful ..it is 10mm too far in, and there are missing welds.  Part of the issue is because the after-market replacement panel is the wrong shape ..and it hasn't been corrected.  The door (by the window slot) is cracked in two places because of previous slamming, but I had replaced the doors latch-mechanism and adjusted the door myself, so that its shut was good.  I was very disappointed then that the door again needed slamming ..because the panels have been aligned without allowance for the b-post's seal.  Had M&T been close-by rather on the other side of the country, they would have had the car back to do that sill again.  I've slackened the door adjustment so that it can be closed again, but now the back edge of the door sits out from the rear wing by 4mm. Beforehand it was flush.

Most of the additional work was supposed to have been done n' dusted while Mark was on holiday, but it's clear that they weren't ..from his photos and the three week delay in then getting the car finished.  I suspect when he came back into work, the next customers car had come in.  And then I feel Katie's sill fitting and final assembly work was hastily done ..unsupervised and not 'done properly'.  I'm saddened that Mark was so let down by his employees ..because he is such a genuine guy - and it's upsetting to predict that those employee's lack of integrity will undermine & destroy his own effort and the company's reputation.    

Perhaps somewhat naively, I hadn't expected to do anything under the car, save lubrication / maintenance and to re-torque fastenings, for the next few years of driving.  Realistically, I had to accept that other things were wrong before the car had its chassis swap - which I had not yet identified because of the wire-wheels were out of balance and the car's overall rattles and shakes.  The car's road testing, subsequent to chassis swap, should have highlighted these to the mechanic, but instead I (the paying customer) had to drive 340miles to test drive and assess the car myself ..in the rain & without fuel, to then gave them a 24 point snagging list.  Katie's chassis is now a solid foundation to build upon - but otherwise I cannot trust, and therefore I'll have to personally check what has been done, and to correct things that we never had issues with before ...whereas I hoped to be enjoying driving the car.

Pete 

 

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5 hours ago, Bfg said:

Perhaps somewhat naively, I hadn't expected to do anything under the car. [...] I now have a solid foundation to build upon [...] whereas I hoped to be enjoying driving the car.

As Gareth says, Pete, your reflections are always deep and enjoyable to read. Always plenty more food for thought: a real reflective diary!

I empathize with your predicament. The upheaval of moving house, then looking for a suitable new home, and where to put Katie too. Then the disappointments, all the delays, when several things got in the way, just when it seemed you could start having fun at last.

It will be fun when these lingering teething problems are out of the way. But, selfishly speaking, will it spell the end of your teaching us all the tecnicalities in such an absorbing style?

Ciao, David

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Thank you for your kind words David,

You make it sound as if this thread is a constant tale of woe and despair, whereas I would like to think it has also shared Hope, enthusiasm, and many experiences with a host of good and kind people, some of whom have become friends.  And then, from my part, there's been a whole lot of learning about these cars ..and the purchase of a beautiful (albeit yet to be sorted out) car called Katie.   Most of this journey has been enjoyable, but then the frustrations have been equally profound too.   It is, I think, an honest appraisal of classic car (..or motorcycle, boat, old house, or whatever) ownership, in particular for those of us who cannot afford to buy a nice example that's already been sorted, or else to pay the same value again (or several times over) in having a professional restoration done. 

My experience with M&T has on the whole been great, but the reality is that anyone who is an optimist and a bit of a dreamer by nature, will be soon be brought back to earth with a bump by reality.  That's not of Mark's doing, it's just that if you pay for one thing to be done then it is to be expected that most everything will remain undone.  The following photo (taken just yesterday) might better illustrate that . . 

P1390645s.JPG.15e8882c5330d526efc13c7bf9d57b9d.JPG

^ this shows the outer RHS rear-trailing-arm bracket with two-notches-up correctly installed to the reinforced and repainted-silver chassis.  You'll note that M&T replaced and fitted re-plated bolts along with two new shims, the brackets were repainted, and that coppaslip was used to prevent each of those bolts from seizing in place in future. The poly-bush was still in good order and the swinging arm is clean and good to go.   But.. aside from that excellent work by M&T, you'll also see that the paint on the underside of the body tub and inner sill is flaking and there's surface rust.   I didn't ask M&T to do that, and so..  "it is to be expected that most everything will remain undone".

As it happens, I didn't know this floor's paint needed to be redone.  Had I been doing the chassis swap myself, then I would have quickly run a powered-wire-brush over those panels and treated them to rust preventative treatment and slapped on a quick coat of paint ..while access was good, before refitting the body to the chassis.  Had M&T advised me of this - then we would have been faced with the issue - that they need to do a good job for the sake of their long-term reputation, and I don't have the money to pay for them to do such a nice job.  Obviously as the car's owner I'm disappointed and upset to see rust starting to appear, especially on a car that's only just come back from a body-off chassis swap, but then on a car which will be kept outside and driven in all weather conditions ...but that is not at all M&T's fault.  It is my friend is just one of many harsh realities of classic car ownership on a budget and where the owner doesn't have a garage.   So I still have the same issue, but access is again poor, and I have to work laying on my back under the car and the seasonal weather is closing in.   

Last week I didn't celebrate my 65th birthday ..I was in an especially foul mood all day and working under the car.  Thursday, I had a good day and enjoyed Mathew's company, but actually did very little.  And then yesterday, Sunday, I was working under the car from 12:15 to 5:30pm.  I then had a shower and was then reading again Buckeye Triumphs  reports on suspension adjustments until 8:20pm. when I had a quick meal while watching a movie,  to distract my mind before bed.  As they say in the movies "I'm getting too old for this ****" ..and although the job list is diminishing and the car is now back to being in safe, sound and attractive condition ..  if I could sell her and the spare engine, for what I've spent on them (at cost price) then I'd just walk away. 

My home would be clear of clutter for just a short while, until I get one of the old bike's in ..to prepare that for sale as well.  As I'm now feeling  too old and tired to be working towards a dream ..and never actually getting there. 

Someone wanting to take over from where I've got to with Katie  isn't going to happen, so I'll just have to continue on.  But then it's no longer a hobby - it's an outstanding job list.  And those jobs don't go away if I put the car into storage for six months ..or 20 years.   So, I'll keep on with dealing with one thing after another until wet and cold stop me again.  It's relentless.

On 9/19/2021 at 4:08 PM, DavidBee said:

It will be fun when these lingering teething problems are out of the way. But, selfishly speaking, will it spell the end of your teaching us all the technicalities in such an absorbing style?

I was sort of hoping that the next stage of the tale would be selective modifications, and then ' The Adventures of '  ..driving some especially fabulous roads and being part of that countryside, with the people I meet and places I stay, dropping in on distant club meetings, perhaps a few roadside repairs and roadside maintenance, other interesting cars and possibly car-collections we encounter.. and so forth.  Hopefully written and illustrated in such a ways as to be enjoyable ..and possibly motivating to others who are restoring their own car.  

Somehow, such adventure just wouldn't be the same in an MX5 (..or whatever they now called).

Pete

 

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Apologies, Pete

Not my intention, at all. It's true what you say. There are so many insights, discoveries, learned snippets and in-depth handling of problems. So true. Your account of the engine rebuild comes to mind.

What I didn't say was that your candid warts and all approach makes these stories even more interesting. To be so open about everything is maybe quite rare. And when the time comes, as it will, the Ring of Kerry and many other fabulous places will still be there for our tours.

Ciao, David

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Expectations v's reality, we've all been there and will continue to amaze ourselves when we fall into the trap for the umpteen time. I for one enjoy reading of both the positive and negative thoughts about classic car ownership, and believe me it was great to see the brilliant work done to the chassis and body to get it to this stage. I also feel your frustration regarding things that if you'd known could have addressed.

The down days will be equally be turned into high ones in time, but for those of us sipping on our mug of tea with a biscuit reading your 'adventures', its all good entertainment. The psychology of a classic car owner is no different to an elite sports person, who has to work on their mental strength, and dig deep in the face of defeat. Hopefully your musings will be both a means to purge your darkest thoughts on this project but also to have a record of progress and satisfaction of that progress.

I'm looking forward to your next fix, perhaps the suspension ride height or a simple but awkward rust protection to the underneath that you've shown, all I know is it will be an enjoyable read and one I look forward to receiving the email notification for.

Gareth 

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Hi Pete

 I bet there is not one person on this forum who has never said " if I could get the money back" I know I have many times under my breath but we carry on things get sorted as my old fitter who taught me use to say" there's always a solution to the problem just got to find it some easier than others" You'll get there next year will be full of joyful outings and meetings then all the woes will be forgotten until?? yep the next one and so it goes on, the ups and downs of owning a classic car but none of us would be without one so your not alone Pete, I find an upside down wooden box and a cup of tea soon gets you back in the groove ( and a couple of beers once you've cleared up)

Chris

 

 

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We spent 2 days replacing an engine and gearbox.

   On filing the replacement engine with water, as fast as I poured it in it dribbled out the water pump seal.  We packed up and I now have the pump on the bench ready for a seal replacement.  Our dad rebuilt that pump 30 odd years ago and gave my brother a spare seal with it, ‘just  in case’.  
 We do have a spare good pump from the old engine but it has a wide belt pulley and the engine is built with a narrow conversion.


It is a hobby, not a business so walking away and tidying up was a good option.

Peter W

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Yesterday was interesting, but not as productive as I hoped ..and my back now aches something rotten.   Nevertheless here we go . . .

Ignoring for a moment the ride height, which I hoped might be helped a little, with what I was about to do - the challenge was to adjust the rear wheel's positive camber. 

But firstly, I needed to ascertain where we were at.

P1390634s.JPG.3aba71ccebcbd26bc4f21991b0718406.JPG

P1390635s.JPG.f9080f90a2fa24ca812c5b46370b840d.JPG

^ eight approx 8kg night storage-heater bricks in each seat, half a tank of fuel, the spare wheel and another 15kg of weight in the boot to simulate normal load conditions.

The car is on the level having been rocked and rolled forward.

P1390637s.JPG.c52f784f2d630697444f41d0052b6dbb.JPG    P1390638s.JPG.72cc5f8dd1a737a8abcc390be0b1f87e.JPG

^ The spirit-level is standing on the floor and leaning against the wheel-arch brow, with a piece of wood leaning against it to hold it steady while I measure to the rims top and bottom.  The dimensions recorded (rear LHS) were 46.5mm top and 50.5mm bottom, so the top of the wheel was tilting out (positive camber) closer to the spirit level rather than being upright or slightly tilting in.

I did a scale drawing of this (on the computer in ACAD) and the angle equated to 0.73 degrees (positive). The TR4A workshop manual tells me it should be +/- 0.5 degrees. Personally speaking I would like to see zero to -0.5 degrees negative camber.  In any case the requirement is to alter the positive camber to negative by about 3/4 of a degree (have the wheel sitting vertically when the car is loaded or leaning in by about 3mm difference) or just a little more.   NB. the difference on the rear RHS of the car was the same 5mm / 0.73 degree positive camber.   It's reassuring when both are the same.

Now, working on the rear RHS of the car, only because that was easier in my present working environment, and with the wheel off this is what we see . . .

P1390648s.JPG.ef896c271841cfc8dfa21345a874be7d.JPG       

^ Taking the chassis rail as being level,  you can clearly see how the trailing-arm brackets adjust the camber of the trailing arm and therefore the wheel.  It ought, by the look of things, to be negative camber (top of the wheel tilting in) as the orientation of the brackets are correct for this car.  The camber does go to negative as the suspension is compressed. This is so.. when cornering - it's like putting the tyre at a very slight angle to stop it sliding sideways.  As it is the tyre leans outwards and the so is scrubbed further under the side wall.  This positive camber then is consistent with the car's ride height being more than it should be (the springs are not compressing enough).

Looking on Buckeye Triumph's report on adjusting the camber ;  I read this . . .

58600545_Trailingarmbracketseffectoncamber2.jpg.e3e7df85046368aacb5816864a4e9760.jpg

^ This records three different bracket shapes, 1, 2 and 3.  each marked with the corresponding number of notches on its top edge.  

Type-1 has the trailing-arm pivot / axis bolt (where the rubber or poly-bush goes) just 3.2mm below the centre of the bracket (between the bracket's two mounting bolts). NB. This type-1 is what I have.. seen to the left of my photo (above). 

Type-2 has its pivot/axis-bolt 9.35mm above the centre of the bracket. This type of bracket is what I have (outboard by the sill) seen to the right in the photo above.

Type-3 bracket doesn't concern me because I don't have those (they're sometimes used on the TR6), but for record their pivot/axis-bolt is some 16.8mm below the centre of the bracket. 

3D-2D means Outside a type-3 bracket with notches Down, used in conjunction with an inside type 2 bracket, also with its notches Down.  In this configuration the camber between the brackets is -4.16 degrees ..which because of the trailing arm's geometry gives -3.3 degree (negative camber) of the wheel. (it say 3.61 degrees in another table). Another row starts with 2U-3U whereby the U signifies that the bracket is orientated with its notches UP.   

Katie  presently had the configuration I've highlighted in blue. 2U-1U ..that is type-2 brackets with their notches facing Up on the outside, and type-1 brackets, also with notches Up on the inside (nearer the centreline of the car).

Editing that table into what is pertinent to me at this time .. insomuch as I only have two type-1 brackets and two type-2 brackets to play with, let's clear all the other permutations away ..and so this is what we see . . .

1178530909_Trailingarmbracketseffectoncamber3.jpg.d33f5f609e4b26f8e78dc444d7ce892f.jpg

^ The configuration Katie  has (correct according the manual) is again highlighted in blue.. Outer ; 2 with notches Up, inside type-1 bracket also with notches Up. 

I want more negative camber by at least 0.73 of a degree ..and the table says to reverse & invert (in red) the brackets I have. That it says would alter the camber by 0.6 degree which is very close to what I want, and the most these particular brackets will give us.  

However to me it doesn't make sense.  Surely if you rotate the brackets 180 degrees ..the angle between them will be the same.?   I wasn't convinced ..but at the same time I remained uncertain, as this report is reputed to be accurate.  Perhaps I was missing something.?  So., I took the brackets off and did what it suggested . . .

P1390651s.JPG.4b067e6d359b5503a0f6f61fbd13d04a.JPG

^ getting those brackets out is a pain-in-the-arse when you're an old fart working under a car on axle stands.  Firstly the road springs had to be removed to take the pressure off them, so driveshaft inner coupling and damper, then the spring could come out, and the trailing-arm pivot-bolts removed, and then finally the bolts holding the brackets to the chassis rail.  Thankfully the corner triangulation / gusset plates I had added didn't restrict access too much but still it was working blind to get the socket in there.

P1390660s.JPG.221d6b5d112243dcd6a6fbaabd1c3533.JPG      P1390659s.JPG.3d988d5a264d093c72ff3b90b6c34339.JPG

^  brackets off the RHS of the car.  The Left bracket with notch Up is type-1 and from the inside, and the right bracket with notches up is the type-2 (which I'm also indicating with the blue masking tape) and that was next to the sill.  on the table this was designated 2U-1U   

^^ RH piccie shows these reversed and inverted as suggested.  On the table above this designated ID-2D.   Nope., the angle didn't suddenly change as I stepped over them to take a photo from that side.  But as I say, I might have been missing something so I put the car's suspension back together again with the brackets this way around.

Then loaded the car up again and bounced, rocked and rolled it forward to the marked-level ground.  But I do admit that I haven't yet driven the car to re-settle the suspension, but for a quick check I presumed this might give us an indication.

Results ;  that side's wheel has adjusted, in part the suspension appears to have dropped by 10mm (wheel centre to wheel arch) which was much more than was predicted in the Buckeye report. This change is in part due to the pivot axis (although the same 2.08 degree angle) being of a different height (as illustrated below) relative to the chassis rail / the bolts on the brackets . . .

1489678292_Trailingarmbracketseffectoncamber4.thumb.jpg.ed5548d515a21f5e444d9c0c2f922773.jpg

^ Drawn to scale, the brackets -3.2mm (type-1 bracket) or +9.35mm (type-2 bracket) offset relative to the chassis rail / the mid axis of the bolts through those brackets.  

Top is how the car's RHS trailing arm brackets were. And across the bottom is how they now are.  And yes as I thought, the pivot's axis angle is unchanged (at 2.08 degrees) and the height relative to the bolt's horizontal axis is lower (by some 6mm).  According to the report this height change should have rotated the wheel, around the spring by " 10.5"/19" or 55% of the change in the bush axis height" ..which translates as lowering the ride height by 55% of 6mm = a little more than 3mm.   For whatever reason my quick check suggests its lowered by around 10mm.   And this is with the M&T supplied replacement road-spring fitted. 

The camber angle did not change by 0.6 degrees, as the table suggests (..so I've not yet gone completely nuts !) but it does appear to altered by almost 1/4 of a degree ..from 0.73 degree of positive camber to 0.51 of positive camber.  Because the angle between brackets has not changed - I might only attribute this change to ; 1. the camber changing according to suspension compression (ride height), and 2. because each of the bracket bolts have been pinched up but not tightened yet, so they have self adjusted with the bushes now being in line and also with any slight slack in the chassis or bracket's holes.

The looseness of fastenings, until the road-spring was refitted, probably also accounts for the noted change in ride height.

- - -

So that's about it.  I think to further correct the camber, I'll need to buy two more type-2 brackets, and to swap them out for the type-1's that are fitted.  This ought to alter the angle between the brackets by almost exactly 1 degree, which will translate through the geometry (according to that report) to -0.87 degree of the wheel.  That would take the present 0.51 deg positive to -0.36 (negative) camber ..which is exactly what I want.   However the ride height will go back up again be 3 or 4mm. 

I think only shorter / lowered springs, or less than 7mm thick collars, is going to help with that.  

 

P1390664s.JPG.15f6d999fcc2eace039bce86cb46e387.JPG

^ Interestingly, or not, from photos taken when I was first looking around under this car.., the brackets this way up (now inverted) are close to what we had before the chassis change. . . particularly evident with the inside bracket (top left in this photo) whose the bottom edge is almost parallel with the bottom of the adjacent chassis leg.

I'm particularly grateful to the gentlemen who wrote the article for Buckeye Triumph  as, although their data is in some parts wrong, they have provided a lot of useful measurements and an overall well-worthwhile insight into the geometry of these IRS components.  BIG THANK YOU to them. 

Pete.

 

Edited by Bfg
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On your picture, the inner trailing arm bolt is fitted the wrong way (the one in the bush sleeve). It should point the same way as the outer bolt.

I know it don't help to remove the arm, but I've seen so many chassis rails pinched by this bolt.....

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1 hour ago, Chris59 said:

On your picture, the inner trailing arm bolt is fitted the wrong way (the one in the bush sleeve). It should point the same way as the outer bolt.

I know it don't help to remove the arm, but I've seen so many chassis rails pinched by this bolt.....

Sorry I don't understand.  How does a chassis rail get pinched by the bush / pivot bolt ?  

Pete

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2 hours ago, ntc said:

You do know that the geometry setup is pointless until your ride height is correct?

Not so,  the amount of change to any of this geometry is defined, so for example the author of Buckeye Triumph article writes "The 0.44” spacer raised the height 0.8” and increased the camber (in a positive direction) by a little over one degree".   I've read the same with regard to the Triumph 2000 rear suspension "Every 0.725” lower at the wheel results in 1 degree of negative camber".   

If my car's ride height were 6" out, then the geometric change would be a little more complicated, as it's non linear, but as Katie's  is within 1 to 1-1/12" of being right, then the variation to camber may be closely predicted from the above figures. 

Similarly with any variation to toe-in. 

Pete.  

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15 minutes ago, Bfg said:

Not so,  the amount of change to any of this geometry is defined, so for example the author of Buckeye Triumph article writes "The 0.44” spacer raised the height 0.8” and increased the camber (in a positive direction) by a little over one degree".   I've read the same with regard to the Triumph 2000 rear suspension "Every 0.725” lower at the wheel results in 1 degree of negative camber".   

If my car's ride height were 6" out, then the geometric change would be a little more complicated, as it's non linear, but as Katie's  is within 1 to 1-1/12" of being right, then the variation to camber may be closely predicted from the above figures. 

Similarly with any variation to toe-in. 

Pete.  

Want to bet? And using a string line on the tyre is also inaccurate 

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:D

 

12 hours ago, ntc said:

Want to bet? And using a string line on the tyre is also inaccurate 

Thank you..  you made me crack a smile there.  A truly nostalgic moment..  "you want to bet ? "  ..I haven't heard that counter-argument since I was a 13-year-old schoolboy.  ;)

 

 

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20 hours ago, Bfg said:

Sorry I don't understand.  How does a chassis rail get pinched by the bush / pivot bolt ?  

Pete

Once fully tighten, some inner trailing arm bolts are long enough to pinch the chassis rail.

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  • 3 weeks later...

Following on with my adjustments of Katie's  rear suspension, from 20th September ..and it's now 12th October - phew but that's how life goes.

Ten days after my op I was down under again.  I'm sure the NHS discharge sheet says something about 'light exercise' including (but not limited to) getting down and back-up again from the floor (x100 times), twisting, crawling and reaching to undo rather tight half-shaft bolts, pumping up n' down on the trolley jack handle, and of course moving 136kg of bricks into and out of the car.

During my convalescence I was struggling to fathom out why suspension adjustments on the car didn't match the figures in Buckeye Triumph reports. So I looked again and picked up a few errors, then remodeled the Trailing-arm geometry for a second time in 3d (Rhino computer program).  I thought about pull together a consolidated report for the benefit of other TR owners, who want to adjust their own suspension (..without special tools),  but in the meantime here are a few tidbits . . .

 

1642585654_Trailingarmbracketseffectoncamber-Rhinomodel.thumb.jpg.cdbb271a7c02688e04cdee3db31403eb.jpg

^ this is one of the 3d computer models I generated and manipulated to try and better assess what was happening to ride height & wheel camber when the trailing-arm brackets are swapped around.   I was working on and so modeled the rear RHS trailing arm of my TR4A.  And so as if viewed from the back of the car, the wheel can be identified in the bottom RHS of this screen capture.  The row of lines at its base are a visual guide to wheel height (best seen from the side view) which of course is a direct representation of ride height.

The black line up from those is a vertical datum, against which I measured the wheel's camber.  The wheel and the green lines (which represent the trailing arm) were joined together as a block, so they might be pivoted as an assembly around the polybushes, in their brackets bolted to the chassis. The row of blue lines near the middle of this image represent the various position / options offered by the selection of three types of trailing-arm bracket. The red line seen running diagonally though those is axis of the polybushes,, around which the arm and wheel-hub, and the therefore wheel itself is swiveled (3d_rotate in Rhino ).  The cyan coloured circle represents the bottom of the coil spring. 

The coil spring, with its vibration insulation collars, have a predetermined length ..for any particular load condition. The TR4A manual suggests setting the suspension up with 150lb (68kg) of weight in either seat.  The top position of this spring length is fixed (within the cup of the bridge on the chassis).  In regard to swapping from one trailing-arm bracket to another..  the height of the polybush axis moves higher or lower relative to the chassis rail.  So then., if the height of the polybushes is moved down (when a different trailing-arm bracket is used) ..and the road-spring has a predetermined length, then the back-end of the trailing arm ..complete with wheel-bearing hub and wheel, go up.  In short, the change in height of the polybush seesaws around the bottom of the road spring. 

It's position was estimated from the dimension given in the Buckeye report. The rough dimensions were 10.5" to the spring and 19" to the hub, but I feel they were incorrect in calculating the effect of height rotation based on those dimensions " If you draw a couple of sketches you'll see that the car height changes 10.5"/19" or 55% of the change in bush axis height "   How's that.?  When I draw a 19" long seesaw with its pivot at 10.5", and then raise the polybush end by 1" ..the other end goes down by 0.81".

I suspect they were also very slightly inaccurate in assuming the axis of the wheel hub was in the 2-dimensional same plane.  In practice the polybushes are quite a bit lower on chassis than height of the centre of the wheel (..as you can see in the illustration above I've drawn the height difference into my 3d model). Conversely the bottom of the spring is down at the chassis level.  I wonder too, if measuring to the centre of the road-spring within the trailing arm is correct.  I'm thinking a drop in polybush height rotates around the front edge of the bottom coil of the road spring. That may not seem like much but again this effects the ratio of change, so instead of 10.5" the dimension I used is 8-3/4".   Referring back to the sketch of a 19" long seesaw, but now with its pivot at 8-3/4".  Raising the polybush end by 1" ..and the other end goes down by 1.17" ..compared to their 55% (0.55") that's a over double the effective difference.  Not only does this effect the ride height, but any suspension travel also changes the angle of wheel camber.  

Moving on. . .

As you can see in the illustration, I've played with the model and listed the effects of changing from one bracket to another. NB. this computer model's adjustment is completely manual, and therefore subject to minor error.  I'll come back to those figures in a short while, but firstly let's quickly review the trailing-arm (bush mounting) brackets . . .

1827717720_Trailingarmbracketseffectoncamber01.thumb.jpg.cfb135143f60503c78d1db6453d878bf.jpg

  ^ this screen capture of my Autocad drawing shows (on the LHS) ;  a plan, side and end view of a bracket. It shows the two mounting bolts to the chassis rail and the one through the polybush (rubber was original and so may be substituted).  Through the side view you can just about make out the yellow centre-line, equidistant from the two bolts.  And from this a dimension of 9.35mm up to the centre axis of the polybush.  With that offset, this bracket is a 2-notch type.  Turned over, on the two bolts, and the offset to the bush would of course be down rather than up.  Not illustrated, but the 1-notch type of bracket has a 3.2mm offset from the yellow centre-line, and the 3-notch type of bracket has a 15.8mm offset.  These figures are very slightly different to those in the Buckeye report because I've assumed they were designed & made to imperial dimensions.. with offset of ; 3/8", 1/8" and 5/8" respectively.      

The two trailing-arm brackets are centred at 13-5/8" apart when mounted onto the chassis (illustrated across the top and bottom of the drawing), and the ends of each blue dashed line (each 1/4" apart), represent the bush centre with each possible bracket position (viewed square-on to the chassis rail).  The brackets illustrated represent a 2-notch and a 1-notch. Drawn to scale the height of the polybush bolt is very apparent, with the ' OUTSIDE ' bracket (left) being higher than the INSIDE bracket.  It looks a lot but the angle between them (seen as the green dashed line) is only 2.08-degrees from the horizontal.

However in detail, the polybush (or rubber) is expected to do this . . .

 230195873_Trailingarmbrackets-ovalholeforcamber01.jpg.4e31ba7a7d3f43daf9ed23634629b6b2.jpg                  P1390692s.JPG.c24769f86498bbf00ddddb177cbb5f35.JPG                       

^ I wasn't happy with that, because it's like hanging a door on hinges which aren't in line,  so..  ^^ on my own car, I've slotted one hole (in either bracket) sideways by a millimetre. The other hole(s) were untouched, and so the bracket's position on the chassis is unchanged, but the slotted hole allows the brackets to tilt so the polybush bolt and pivot axis are in line  (ie., the whole bracket now sits at that 2.08-degree angle rather than torturing the bush). 

Anyway back to the figures I took. . .

The TR4A with standard ride height, wheels, tyres, etc., was designed with a 2-notch bracket (notches Up) on the OUTSIDE and a 1-notch bracket (notch Up) on the inside.  Then, at the correct ride height / loaded according to the workshop manual's specification (a nominal 150lb / 68kg on each seat), the rear wheel's camber would be zero, +/- half a degree. ie., they would be vertical - That's easy.   And so that's how I set my computer's 3d model up. 

I modeled what I had on my car ; with the 2u-1u brackets, and its ride height being a little high, and its +0.73 degree wheel camber ..and then rotated the 3d 'trailing arm, hub & wheel assembly' around the polybush axis until the wheel camber measured zero.  This was the equivalent of lowering the suspension by almost 12mm.  

This gave me the as-designed  Standard rear suspension geometry.  Then I systematically changed the type of bracket and their orientation (up or down), and for each I rotated the back end of the trailing arm back to where it touched the bottom of the road-spring (that having a predetermined length for that load condition), and measured the consequential height and camber of the wheel.  The results were as follows . . .

            Brackets   Height    Camber (degrees) ;

  • 3d-1d        +6.59        +0.83
  • 2u-1u          0.00 mm     0.0 
  • 1d-2d        - 6.53        - 0.83 
  • 1u-3u      - 12.50        - 1.63

 Then tilt the bushes one notch and repeat ;

          Brackets    Height    Camber

  • 3d-2u      + 11.58       + 2.30
  • 2u-1d        + 5.00       + 1.47
  • 1d-1u         - 1.50       + 0.64
  • 1u-2d         - 7.93       -  0.19
  • 2d-3u       - 14.29        - 1.02

The first thing you'll notice is that, compared with the Buckeye report's table (submitted in a previous post), there are very few results.  This is because reversing the brackets (inside to outside) so the trailing-arm bush would be lower on the outside bracket, isn't (for all practical purposes) likely to happen. If that extent of camber change ..to positive, is required, then it very much points to the chassis having collapsed in the middle.  Similarly, if the same type of bracket is used both on the inside as outside ..whereby the bush axis would be parallel with the (supposedly horizontal) chassis rail.  Only if a car is custom-lowered might those bracket configurations be required, and those are outside the remit of my investigation.

The second thing you'll note is that I've presented the figures in two parts. The first four bracket configurations are simply moving the axis up or down, from standard, with the 2.08 degree angle of the polybush axis (relative to the chassis) remaining the same.  The second set has tilted the bushes one notch (one degree greater angle) and then again moving that polybush axis up and down.  

For those who prefer here is a graph representation of the above figures . . .

1980966532_Bracketselectioneffectoncamberandrideheight-10thOct.jpg.d4ee600889013b501814d53f8b82c972.jpg

^ Mostly speaks for itself, but the grey grid lines are from the first four bracket configurations and those with the green grid lines are from the last five.  Those with the blue lines are the datum (standard TR4A set up) from which the others are measured. This means that the figures are relative (..albeit hand measured). So anyone adjusting their own car's suspension (whether TR4A, TR5 or TR6, or Triumph 2000) has to firstly accurately establish what they have, and then to adjust from that datum.  

The graph is easy enough to read insomuch as if you were to change from the standard (blue grid lines) bracket configuration of 2u-1u (outside bracket - inside bracket) to 2d-3u (found as the lowest red dot in the bottom left hand corner), then you might expect a 14+mm (14.29mm) drop in ride height and the wheel camber angle would tilt towards the negative by 1.02 degrees. 

This is what I did on my car (this last weekend) and the car did indeed drop in height and the RHS rear wheel's camber is now -0.30 degrees.  Starting off from +0.73 minus 1.02 = -0.29 degrees  ..so what I predicted was achieved (+/- 0.01 degree).  That is on the RHS of the car.  The LHS of my car is sitting 10mm higher, and so has a tad little less camber (it is now negative though).  I'll (hopefully this week) correct this by swapping the spring collars out for thinner ones.. The ride height will drop and so the wheels camber will tilt a little more to the negative.

P1390708s.JPG.38f844d26042824a7649e4ef1d1d9623.JPG

^ after swapping out the trailing-arm brackets, I'm checking the camber angle of the LHS rear wheel.  I have each seat loaded with approx 64kg of night storage heater bricks, and the ground has been leveled (with a piece of 1/4" plywood under the RHS rear wheel).  The car was lowered, loaded up and bounced upon, and moved forward onto plastic bags (which are a poor man's slipper plate, to allow the tyres to slip sideways and otherwise settle where they will). The car was bounced upon again to allow it to settle without the tyre's wanting to scrub sideways.  The spirit level is vertical and aligned to a mark on the wheel-arch (so the same place is measured from each time) and then the dimensions to the top and bottom of the wheel rim was recorded (in this instance just 1mm difference between top and bottom). With 395mm height between rim measurements, the figures were used in a drawing (on the computer) for it to tell me the camber angle was -0.15 degrees.  

Hey ho., getting really close to what I want.  This (above) is the side which is 10mm higher, and although I'll lowering it ..it already looks much better than as the car was sitting when I collected it after the chassis swap.  It then had both a higher ride height and the wheel had positive camber ..measured as 5mm difference between top and bottom (wheel rim to the spirit level) = +0.73 degrees).

How much difference will lowering make ?  Well, while I had the computer model open I checked.  Again using the same 2u-1u brackets as a Standard setting to assess these things from, I rotated the trailing arm around the polybush axis to simulate a change in ride height (whether caused by car load, cornering load, or alternative spring length) and here's the figures . . .

          Brackets   R/Height    Camber

  • 2u-1u          +30mm     + 1.94
  • 2u-1u          +20mm     + 1.29
  • 2u-1u          +10mm     + 0.65
  • 2u-1u              0.00        0.00
  • 2u-1u           -10mm      - 0.64
  • 2u-1u           -20mm      - 1.33
  • 2u-1u           -30mm      - 1.94 degrees

Those same figures present in graph format . . .

1325440960_Springlengtheffectonwheelcamber-10thOct.thumb.jpg.70ada832b9465babc6098d42711f390d.jpg

^ Again self explanatory. The figures (red dots) are again from the hand manipulated computer model and were close enough to set a line through (the -20mm figure along the bottom was adjusted by 0.03 deg to fall into line).

From this I can see that if I drop the suspension on the rear LHS of the car by 10mm, it will have a -0.65 degree effect on that wheel's camber.  However when doing this I also have to factor-in that the tilt of the car (over a 48-1/2" track of the rear axle) is about 0.4 degrees, and so the net result will be closer to -0.25 degree.  But then the camber on the RHS corner will also alter.    

With this information I can get it right (..with a fraction of the trial and error of spanner work under the car), or I can determine how much effort is it worth versus whether I'll actually notice the finer aspects of its adjustment.   Most likely I'll drive the car a little, let the springs settle into their poly-bush collars and reassess things later on.

Out of interest though  . . . 

I was interested to assess the car itself when removing the passenger, and adding more weight into the driver's seat.  I'm 105kg so I loaded 13 x8kg bricks into the driver seat and all off the passengers.. 

The ride height (hub centre to wheel arch) on the passenger side went up by just 6.5mm, and the camber changed by +0.15 degree ..taking that side to zero camber. 

The ride height (hub centre to wheel arch) on the drivers side went down by just 2mm, and its camber changed by -0.29 degree ..also taking that side to zero camber. 

Interesting !

     These are of course static loads and the camber would change when the suspension is loaded ..around corners.

Have a good one,

Pete

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6 hours ago, Bfg said:

From this graph I can see that if I drop the suspension on the rear LHS of the car by 10mm, it will have a -0.65 degree effect on that wheel's camber.  However when doing this I also have to factor-in that the tilt of the car (over a 48-1/2" track of the rear axle) is about 0.4 degrees, and so the net result will be closer to -0.25 degree.  But then the camber on the RHS corner will also alter.    

..the question is ; would these estimations be right. ?

These are the spring collar options I have available to me at this time . . .

P1390744s.JPG.3e504ed4cc94950b7e0ac3407c3bffc3.JPG

^ Top left is a rubber collar, as previously fitted, the spring sits on the rim whose thickness is about 1/4" (6mm) which soon squashes down to being 4 - 5mm thick.  To the right of that is the poly-bush collar fitted by M&T, which as you can see has a larger overall diameter and a thinner inside brim. Its rim is 7-8mm thick and so probably soon squashes down to 5.5 - 6.5mm thick.  Bottom right is one of the rubber collars previously fitted under this car's front suspension's coil spring.  Larger in diameter and its rim is only 1/8" thick, but the impressions of having been used suggest that it doesn't squash down very much at all., let's say to 2mm. 

P1390747s.JPG.73971738aa55173571d8e5687cb60a3c.JPG

^ By way of comparison ; the plastic coil spring collar, held back to back with the rubber collar from the front suspension spring. The huge difference is obvious, so its interesting that both fit onto the rear. Naturally the difference in thickness reflects in overall spring length, and therefore the car's ride height.  

An advantage of the larger diameter rim is that it avoids this . . .

P1390743s.JPG.4f73d9067cdf5a15ed9c45f825d2e944.JPG

^ the collar seen squeezed out from under the spring ..when the spring load was reapplied.  Clearly isn't going to do it job so it had to come out again. Perhaps it should have been assembled dry.?  Anyhow it happened both top and bottom of this spring and so I used the new rubber collar (kindly supplied to me by M&T ) at the top, in place of this previously used and slightly contorted one, and then I used the front spring's large diameter collar at the base, within the trailing arm's recess.

P1390748s.JPG.540b68f956deef96e513636e5396c114.JPG

^ The front spring's collar is a larger diameter (inside out out) but just about squeezes into the rear coil spring, and then sits well in the trailing arm's socket.

So with those swapped out, it was time to lower the car, load it back up and re-assess the car's ride height and rear wheel cambers. . .  

The results are perhaps a little better than hoped, with the LHS of the car dropping from 396.5 to 381mm, so 15.5mm.   As before, the measurements were from the underside of the wheel-arch to the wheel-hub centre and so is independent of tyre size or pressures.  That's more than I had previously planned (which was 10mm) and is a result of my using the very thin front spring collar in lieu of the original type rubber one.  I'm happy with that ride height, as recorded as a static load with 150lb driver and passenger.   I suspect it'll settle a little more with use ..which will then be even better for when I drive alone.  The camber of that wheel has changed just a little more than predicted, because the ride height was changed more. So rather than -0.4 degrees it now measures as -0.44 degrees, which is a tid-bit of a bonus ..as my arbitrary target was -0.5 degrees. 

The RHS of the car, although its suspension was untouched, measured a drop in ride height of another 4mm. The only explanation that comes to mind is that the car is now sitting level rather than on a tilt. Whatever the reason, I'm glad for it.  The ground clearance under the chassis side rails (one side to the other) is within 1/16", with either side now sitting between 5-11/16" and 5-3/4".  I'm very happy with that too.  Its negative camber has increased because of the car's tilt being corrected, and now measured as -0.94 degrees ..which is more than my target. 

Next I altered the load condition once again, to simulate no passenger and with me (105kg) driving.

Without the weight in that side, the LHS rose by 11mm   but the reversed tilt of the car changed its camber to be -0.51 degrees.  I like that.   

With the additional weight in the driver's seat, the RHS of the car dropped by 5mm and the camber (because of the car's tilt) swung back to -0.58 degrees.  I like that too ..but for the implication that I ought to loose some weight !

That's it.,  the rear suspension is set up to where I wanted it for solo driving.  The rear's ride height is now acceptable (..the body mounts are new & thick so the body is a tad high on the chassis but I'll live with that)..  and the car is even from one side to the other.  You may recall before the chassis swap Katie  was riding particularly low on the RHS.  Most importantly for handling, the rear wheel camber on either side is so close to my target figure that...  I'll not write more about it .!

I just need to crawl under the car once again to tighten all the bolts up in this load condition. Then it'll be..  Job done.! 

And if i can do it without specialist tools, then so can you

Bidding you a good evening,

Pete.   

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