Jump to content

Front Suspension concerns


Recommended Posts

My TR6 doesn’t feel right or handle with any confidence for me and I’m trying to understand why. I’ve noticed a number of things which I’m concerned about and any help would be appreciated please.

It has standard springs  all around and Spax dampers front and rear ( telescopic), it’s been poly bushed but the documentation that I have for that dates back to 2007! It might therefore all be a bit tired? There is no obvious movement and visually it all looks in reasonable condition on the face of it. 
These are the things I’ve observed.

1, The fulcrums are fitted correctly with the bigger curve inward

2, The upper arms are fitted correctly with the ‘L’ marking being upper on the NS (U.K. rhd car) 

3, The steering rack has nearly twice as many threads exposed on one side to the other and it’s clear it’s too far over. I suspect the toe is miles out as well.

4, The amount of packing on the lower arm brackets is all over the place. OSR 5 packers, OSF 0, NSR 1 , NSF 7 . The photos show both sides of the NSF with the packers and the scary amount of threads that the nuts and spring washers are holding onto!

5, There are no trunion steering travel limiters fitted so slow speed full lock is interesting to say the least. 

6, The NSF wheel seems to protrude from the wheel are more than the OSF.

7, The amount of packing on the NSF does appear to have pulled the anti roll bar over a bit.

Surprisingly it goes down the road straight and doesn’t pull either way in a straight line.

So where do i start? 
 

Set the toe correctly and properly centralise the rack and see how it feels? 
Pull the whole lot apart and check every joint, ball joint etc etc?

Set the Toe(hopefully) and get the other geometry checked and pull all of the spacers and start from scratch rectifying that horrible NSF lower mount bracket fixing? 

I’ve looked at chassis frame and as far as I can observe it doesn’t look bent. I’ve taken some rough measurements chassis to body each side to compare and it seems consistent.

Any thoughts greatly appreciated as I’m not sure what’s normal in terms of spacers etc or where to start.

Many thanks

Adrian 
 

 


 

 

 

 


 

 

 

 

 


 

 

EE76B805-F8C9-4F84-BF92-86ACDDF236C4.jpeg

C6289A91-D5EF-462C-8979-D19A6511514B.jpeg

30DD5FFB-79FC-4C0E-9D30-077E6827C263.jpeg

Link to post
Share on other sites

Centralise the rack, remove the jumble of packers in the lower inner mounts and start again with 3 packers in each mounting point, fit the lock stops and then get it 4 wheel aligned properly.The yellow polys maybe a bit hard but probably still OK but worth checking the inner spacer tubes in them arent worn.

Stuart.

Link to post
Share on other sites

Adrian, good morning.  

I'd agree with both Stuart suggestions and John's query.  

In regard to the packing and rack adjustment - the prior owner must have been trying to fix something ..and then accepted what was obviously wrong to him in trying to achieve a better result.  Clearly you recognise this as you have being looking for signs of accident damage.  I presume you have looked closely at the wishbones and the link arms from the steering rack to see if they are not bent, perhaps as a result of impact with road debris. As you don't mention it I gather there is nothing obvious.

From the packing and adjustment it would seem as if the prior-owner was trying to correct tracking to one side , ie., crabbing.  Might I suggest (before you make any adjustments at all) - you establish and record how the car is presently set up.  Simply pulling a cord around all four tyres (appropriately packing for any difference in front / rear axle track width) will help you assess both the front and rear axle's toe-in..  Simply measure from each side (ie. at 3-o'clock and at 9-o'clock positions) of a wheel rim to the cord to see if both the front and rear wheels are aligned. They should be straight or with just a tiny amount of toe-in. ie. the two dimensions of each wheel ought to be the same (zero toe-in) or the front dimension might be as much as 1.6mm greater (has a little toe-in, but is still correct).  Well that's correct for a TR4A ..perhaps toe in is different for a TR6 ??    

Otherwise, the prior-owner might have been trying to correct the camber of the wheels by packing things out.  Again this is easy to quick check by moving the car forward onto a level surface (a piece of wood under one or two wheels can help level slight driveway angles) and then checking the wheel rim distance (12-o'clock and 6-o'clock positions) against a vertical spirit-level.  Again as a starting point each wheel ought to be near vertical (with my TR4A) ie the distances measure to the top of the rim and to the bottom of rim should be very close to being the same ( +/- 1.6mm).  If they are not then that might account for why the ' NSF wheel seems to protrude from the wheel-arch (?)  is more than the OSF '.

One final suggestion might be in your appraisal / description of the car's handling.   Where is the car not right ?   Is it in the steering (too light,  vague, unpredictable, over steering, under-steering) ?  &/or is it in the dampers and springs (car rolling, bouncing, skippish over road undulations or bump) ? and is that when going around a left hander or right hander or both.?  Is there any clonking from the suspension, are you feeling something odd through the steering-wheel ?

It is rather difficult to explain some feelings I know, for example I had a live axle Jaguar saloon at one time where the suspension had been 'upgraded' to poly-bushes ..and even down a straight but undulating road it felt as if the car was riding on rather than in its suspension. The steering itself seemed fine (in its weight and in direction) but the tail of the car seemed to float around in the air, from side to side, up n' down and in a sort of twisting rotation, and so fine steering corrections were constantly needed.  Such a description may seem equally vague but it does help pin-point the places to look.  Another example ; too low a tyre pressure can make a car feel squirmish (as the side walls flex too much) and, if the tyres are correctly inflated, then that description might point to flexing or slack in suspension joints.  Naturally the feel of the car also changes when there is a passenger.

Hope these thoughts help you, if only a little, 

Pete.  

 

Link to post
Share on other sites

Before I touch anything I would have front and rear wheels measurement completely.

Anyway the lot of shims and the nuts not fully on the bolts is not acceptable.

It is a hint that there is something severely wrong and if kept I would go and weld in longer bolts.

 

Link to post
Share on other sites

Hi, thanks for all of the info. It’s much appreciated.

Before I’d read any of the responses I’d made a start. I removed the track rod ends both sides and had a general feel and nothing obviously worn or bent. I centralised the steering rack and did a basic parallel setting using a couple of straight edges fore and aft. This has already improved the overall feel and it doesn’t pull either way and it feels like all the wheels are going in the same direction with self centering reasonable. Stuart you mention the yellow Poly’s are these generally pretty hard? They are in every bush. Which bushes would be a bit more forgiving should I replace them? I’m inclined to go back to basics as you’ve said and remove all the spacers and equal pack to see how it looks before getting the geometry measured properly. Is it ok to remove the packers by just undoing the brackets a bit and sliding them out or does the arm need a bit of support underneath whilst it’s on my lift? Is it worth going to zero packers to start with? I’m sure the excessive NSF packs are tugging it all over that way and it would be nice to see what it does without any? 
 

John the tyres are 195/65 15’s and are at 27 psi all round at the moment. Does that sound reasonable? 

In its current state the OSF wheel does appear to be set back a bit, which component would most influence fore and aft dimension? Is it possible that to have a trunnion that is incorrect? I’m aware that the lower chassis bracket mountings or damage could alter this but they look ok. Could it be a component issue? 

Pete, the camber on all four wheels according to my inclinometer shows all of them with a bit of negative camber of 1-2 degrees. Even after years in the motor trade I find it difficult to describe how it felt particularly as I’d never driven a TR6 before. It felt like it was all working against itself and whilst it went straight turning effort seemed difficult in every direction, not surprising really with the toe probably miles adrift. 

V8, I couldn’t agree more. It’s totally unacceptable and awful practice. It smacks of someone not really knowing what they are trying to achieve and compounding the problem with every action taken. If it’s bent it’s bent and no amount of sodding around is going to correct it. I’m not convinced it is as yet so I’ll get measured when I’ve had a further play as indicated above. 
 

Thanks to everyone for their help and hopefully you can ‘steer’ me a bit more on what I’ve just said! 
 

cheers

Adrian 


 

 


 

 

Link to post
Share on other sites
23 hours ago, stuart said:

Centralise the rack, remove the jumble of packers in the lower inner mounts and start again with 3 packers in each mounting point, fit the lock stops and then get it 4 wheel aligned properly.The yellow polys maybe a bit hard but probably still OK but worth checking the inner spacer tubes in them arent worn.

Stuart.

Hi Stuart thanks for the info. I’ve added a detailed reply that I’d appreciate your thoughts on please?
 

kind regards 

Adrian

Link to post
Share on other sites
21 hours ago, Bfg said:

Adrian, good morning.  

I'd agree with both Stuart suggestions and John's query.  

In regard to the packing and rack adjustment - the prior owner must have been trying to fix something ..and then accepted what was obviously wrong to him in trying to achieve a better result.  Clearly you recognise this as you have being looking for signs of accident damage.  I presume you have looked closely at the wishbones and the link arms from the steering rack to see if they are not bent, perhaps as a result of impact with road debris. As you don't mention it I gather there is nothing obvious.

From the packing and adjustment it would seem as if the prior-owner was trying to correct tracking to one side , ie., crabbing.  Might I suggest (before you make any adjustments at all) - you establish and record how the car is presently set up.  Simply pulling a cord around all four tyres (appropriately packing for any difference in front / rear axle track width) will help you assess both the front and rear axle's toe-in..  Simply measure from each side (ie. at 3-o'clock and at 9-o'clock positions) of a wheel rim to the cord to see if both the front and rear wheels are aligned. They should be straight or with just a tiny amount of toe-in. ie. the two dimensions of each wheel ought to be the same (zero toe-in) or the front dimension might be as much as 1.6mm greater (has a little toe-in, but is still correct).  Well that's correct for a TR4A ..perhaps toe in is different for a TR6 ??    

Otherwise, the prior-owner might have been trying to correct the camber of the wheels by packing things out.  Again this is easy to quick check by moving the car forward onto a level surface (a piece of wood under one or two wheels can help level slight driveway angles) and then checking the wheel rim distance (12-o'clock and 6-o'clock positions) against a vertical spirit-level.  Again as a starting point each wheel ought to be near vertical (with my TR4A) ie the distances measure to the top of the rim and to the bottom of rim should be very close to being the same ( +/- 1.6mm).  If they are not then that might account for why the ' NSF wheel seems to protrude from the wheel-arch (?)  is more than the OSF '.

One final suggestion might be in your appraisal / description of the car's handling.   Where is the car not right ?   Is it in the steering (too light,  vague, unpredictable, over steering, under-steering) ?  &/or is it in the dampers and springs (car rolling, bouncing, skippish over road undulations or bump) ? and is that when going around a left hander or right hander or both.?  Is there any clonking from the suspension, are you feeling something odd through the steering-wheel ?

It is rather difficult to explain some feelings I know, for example I had a live axle Jaguar saloon at one time where the suspension had been 'upgraded' to poly-bushes ..and even down a straight but undulating road it felt as if the car was riding on rather than in its suspension. The steering itself seemed fine (in its weight and in direction) but the tail of the car seemed to float around in the air, from side to side, up n' down and in a sort of twisting rotation, and so fine steering corrections were constantly needed.  Such a description may seem equally vague but it does help pin-point the places to look.  Another example ; too low a tyre pressure can make a car feel squirmish (as the side walls flex too much) and, if the tyres are correctly inflated, then that description might point to flexing or slack in suspension joints.  Naturally the feel of the car also changes when there is a passenger.

Hope these thoughts help you, if only a little, 

Pete.  

 

Hi Pete, I’ve added one detailed combined response that I’d appreciate any comments on please? 
 

I notice you are in Suffolk as well, I’m in BSE. 
 

kind regards 

Adrian

 

Link to post
Share on other sites

The lower inner shims can indeed be removed by slackening the nuts slightly and then sliding them out. I would still start with 3 shims on each as thats the nominal setting, the yellow polys used to be described as "Fast road"  so they are harder than standard blue in theory but it depends on whos they are as different companies use different colours regardless of shore. That size tyre is ok and pressure is a bit subjective, I start at 26f 28r and work around it to see what suits the car best. How old are the tyres as that can make a huge amount of difference to handling and old tyres can make it feel like your driving on marbles.

Stuart.

Link to post
Share on other sites

Have you got a four wheel wheel alignment. All the mods might have been done to get the alignment right.

I use at least 30 psi in modern tyres. The thin sidewalls flex if the pressure is too low. Ask a tyre centre and they will inflate them to 36 psi.

I wouldn't change anything until you have the alignment measurements and try higher tyre pressures.

Edited by John McCormack
Link to post
Share on other sites

Hi Adrian, 

As a starting point, I would not think those pressures are a mile out.

Have you actually checked the pressures? For me I'd probobly go 28Fr and 30 Rr, but to be honest, 27 all round wouldn't cause you massive problems.

You could also check whether any of the tyres are feathering or wearing unevenly.

John.

Link to post
Share on other sites

Adrian,

You wrote that you've centered and correctly adjusted the tracking of the front wheels and you've road tested the car, and then "This has already improved the overall feel and it doesn’t pull either way and it feels like all the wheels are going in the same direction with self centering reasonable."    I took this to mean that you no longer have an issue with steering or handling, but you still had to address the unsatisfactory state of assembly and shimming.

You don't mention whether the toe-in of the rear wheels has yet been checked.  Otherwise, I've not much to add to my previous post, not least because I don't know what the recommended camber setting is for your model and set-up of TR6.  As I said above it's +/- 0.5 degree on the TR4A, both front and rear. so one to two degrees would be excessive. 

You've said that you've visually checked and also measured for chassis damage and bent suspension components, which I take to also include the lower wishbones that might have been impacted.  Aside from the shims, I take it the wishbones and their bushes have been assembled the same on one side of the car to the other.  Thereafter if one front wheel appears to be further forward than the opposite, then perhaps the straight-ahead castor angles are different.? 

Regarding tyres, I know little of TR6 wheels and the choice of tyres.  On my TR4A  I have 165/80 profile tyres, as for general road use I don't like the more juddery ride of low profile.  On a track I'd accept lower profile for the benefit of tighter control, but on public roads, I've found that tall tyre sections are more forgiving over road imperfections too (ie., less skittish).  It's all a matter of preference, although very often even that is influenced by what an owner thinks looks 'great'.

On the subject of tyre pressures..  I do however have an enthusiasm and some expertise in post-war Sunbeam motorcycles. Their model S7 was originally specified with 4.5 x 16" F and 4.75" x 16" R.  These would have been full profile crossplys and were run at just 18 - 20psi pressures (F-R).  NB. The early bikes had springs but no dampers in their suspension, so lower tyre pressures helped prevent bounce.   Anyway, I spoke directly with the technical department at Avon Tyres and asked them what pressures ought to be used, seeing as the original sizes were no longer available and most owners were now fitting their Speedmaster Mk2 tyres in 5.10x16 (F & R).  Although these are a "classic" design of tyre - the technical chap, who actually designs tyres for all sorts of road vehicles, said that none of their current tyre range had been designed to run continuously at less than 30psi.    He explained that tyre construction and material compounds have changed, sometimes obviously but often more subtly. Avon cannot accept any liability for damage or uneven wear caused by driving or riding with any less.   However, in the exceptional circumstance of these bike's tyres having, in part, to do the job of dampers too, he unofficially suggested 28psi front and 30psi rear.  He advised against any lower than that.  I now ride my bikes with those tyre pressures and am happy with the compromise between ride comfort, handling, and safety.

The TR4A I'm presently running on brand new Continental C22's with 30psi (F&R)  ..but I too need to correct my suspension's settings before I start to play around with those. 

Hope that helps,

Pete.

  

Link to post
Share on other sites
2 hours ago, stuart said:

The lower inner shims can indeed be removed by slackening the nuts slightly and then sliding them out. I would still start with 3 shims on each as thats the nominal setting, the yellow polys used to be described as "Fast road"  so they are harder than standard blue in theory but it depends on whos they are as different companies use different colours regardless of shore. That size tyre is ok and pressure is a bit subjective, I start at 26f 28r and work around it to see what suits the car best. How old are the tyres as that can make a huge amount of difference to handling and old tyres can make it feel like your driving on marbles.

Stuart.

Thanks Stuart, tyres are newish and all in good condition. I’ll start with geometry and think about bushes etc later. I’ll record the current settings before I pull any out and keep as a reference point in case I make it worse! Whatever happens I’ve got to try and resolve the completely unacceptable assembly that I current have. 
Cheers 

Adrian

Link to post
Share on other sites

Hi Adrian,

Not sure if you have checked... Are the upper wishbones/arms the same length on each side of the car?

I am currently doing a body-off restoration of a US TR6 and I found the wishbones on the left to be longer than on the right hand side. Either the length of the TR6 wishbones changed sone time during production or one set is from a different model (they look identical and have the L/R marking so presumably are both Triumph). The difference in length, from centre of bush on fulcrum to centre of ball joint in vertical link, is about 3/4", which creates a huge difference in camber for the same shims.

Paul

Link to post
Share on other sites
12 minutes ago, paul83 said:

Hi Adrian,

Not sure if you have checked... Are the upper wishbones/arms the same length on each side of the car?

I am currently doing a body-off restoration of a US TR6 and I found the wishbones on the left to be longer than on the right hand side. Either the length of the TR6 wishbones changed sone time during production or one set is from a different model (they look identical and have the L/R marking so presumably are both Triumph). The difference in length, from centre of bush on fulcrum to centre of ball joint in vertical link, is about 3/4", which creates a huge difference in camber for the same shims.

Paul

Hi Paul, thanks for that. Definitely one I’ll check ASAP.

Thanks 

Adrian

 

 

Link to post
Share on other sites
1 hour ago, paul83 said:

Hi Adrian,

Not sure if you have checked... Are the upper wishbones/arms the same length on each side of the car?

I am currently doing a body-off restoration of a US TR6 and I found the wishbones on the left to be longer than on the right hand side. Either the length of the TR6 wishbones changed sone time during production or one set is from a different model (they look identical and have the L/R marking so presumably are both Triumph). The difference in length, from centre of bush on fulcrum to centre of ball joint in vertical link, is about 3/4", which creates a huge difference in camber for the same shims.

Paul

Paul are they shorter or longer than the correct TR6 ones?
Thanks 

Adrian

Link to post
Share on other sites

Hi Adrian,

The short answer is that I don't know...

I raised the issue on the Forum here: TR6 Forum: different-upper-wishbone-arm-lengths, which suggests that the shorter pair are TR4. The general consensus is that TR4A - 6 use the same (longer) wishbones, and the TR4 (not A) uses the short.

However I cannot confirm this because I cannot find the specification length of the wishbones in the TR6 Brown Book or anywhere else. An addition, I purchased new upper wishbones (for the TR6) from Moss and they are shorter than the long pair I had, and the same dimensions as the short pair. Moss could have sent me the wrong pair.

So I am in the process of installing the shorter wishbones. I suspect that as long as both sides match, the only issue is the camber angle.

 

Whilst rebuilding the suspension, I discovered something that you might also want to check: on my car, one of the rear mounting plates, which is welded to the chassis behind the turret and where the lower wishbone bracket is bolted to, is out of line with the front plate (and out of line with the front and rear plates on the other side of the car). It has obviously collapsed/ been bent at some point in the car's life and then someone has welded on new plates either side to add strength. But in adding the strengthening, the plate has been fixed out of position. The upshot is that this particular plate/ bracket needs extra shims to align the lower wishbones. The rear has four shims and the front has 2 shims, and the wish bones marry up in the same was as the other side of the car which is straight.

Nothing is ever straightforward!

Paul

Edited by paul83
typo
Link to post
Share on other sites
On 9/21/2021 at 9:58 AM, stuart said:

The lower inner shims can indeed be removed by slackening the nuts slightly and then sliding them out. I would still start with 3 shims on each as thats the nominal setting, the yellow polys used to be described as "Fast road"  so they are harder than standard blue in theory but it depends on whos they are as different companies use different colours regardless of shore. That size tyre is ok and pressure is a bit subjective, I start at 26f 28r and work around it to see what suits the car best. How old are the tyres as that can make a huge amount of difference to handling and old tyres can make it feel like your driving on marbles.

Stuart.

Hi Stuart I’ve done some measurements in its current state.

My initial basic tracking adjustment has resulted in 2* Toe in 1* measured each side

Rear track is NSR .25* Toe in and OSR 0.6* Toe in. Rear camber NSR - 1.0* OSR - 0.5*

NSF camber is + 0.2* Castor -0.5* KPI 11.75

OSF camber +0.6* Castor +1.25* KPI 10.5

Any thoughts on that lot before I pull and repack the shims and re-measure? 
 

Does packing the front or rear increase the castor? Spec looks to be + 3.5 ? 
 

Thanks 

Adrian 

 

 

 

 

Link to post
Share on other sites

Castor isnt adjustable as its set by the trunnion angle and should be 3 degrees. the camber should be 0degrees laden. sounds as if you have either worn out bushes on either inner or outer lower bushes or something is bent, do you have the turret brace fitted?

Stuart.

Link to post
Share on other sites
2 hours ago, stuart said:

Castor isnt adjustable as its set by the trunnion angle and should be 3 degrees. the camber should be 0degrees laden. sounds as if you have either worn out bushes on either inner or outer lower bushes or something is bent, do you have the turret brace fitted?

Stuart.

Hi Stuart, forgive my TR6 ignorance but what’s the turret brace and where’s it fitted? Is it an additional item. 
 

I’ve pulled all the packers out and refitted 2 in the front and rear both sides.

I’ve remeasured and the OSF isn’t bad

Camber + 0.75

Castor + 2.5

KPI 8.5

The NSF is a different story

Camber + 0.75

Castor - 2.5 a 5 degree swing to spec

KPI 15 !!
 

I think its all about what’s wrong NSF now. Bent frame, bent/wrong component. What’s your thoughts? Wheel definitely sits back compared to OSF, just looks wrong. I’ll have another look tomorrow on that side. 

Thanks so much for your help, much appreciated.

kind regards

Adrian
 

 

 

 

 

 

 

 

Link to post
Share on other sites

I would also check the trunnion is correct on the nsf I have heard of 0 degree trunnions being fitted accidentally though never seen it myself. The turret brace is a tube that goes between the the front suspension turrets in front of the engine just over the fan pulley. Part 54 in. The moss diagram 

https://www.moss-europe.co.uk/shop-by-model/triumph/tr5-6/body-chassis/chassis-subframes/chassis-frame-tr5-6-1967-76.html

Edited by Kiwifrog
Technical
Link to post
Share on other sites

Adrian,

Apologies if it has been mentioned above but I could not see mention. Tyres have you looked at the age of the tyres? The dot codes. I just wondered if you have a  single aged tyre on the front - irrespective of pressures etc.

My experience, II had minor handling issues with my car, it seemed to be different on RH corners but had to tell on the varying UK pot holed roads. I had my car corner weighed - cost me £25. There was a significant difference it the front wheels, as I recall about 50 lb.  The car was like a wobbly pub table (without optional beer mat under leg). Working out the poundage of the springs. 50 lb  equated to about 3mm. A 3 mm shim was fitted and the front weights were even. Afterwards the car was different, perhaps I imagined it, but cornering seemed more even, more like running on rails than previously.

Not suggesting you rush off to have it done, but perhaps when you have sorted every other thing out it might be another avenue.

Alan

 

Link to post
Share on other sites

Your camber still isnt right as it should be 0 so probably another shim in the lower inners would make that right (I did say start at 3) but that castor is way out, you need to check exactly what you have there as something is way out, it may well be you have a bent turret or incorrect trunnion or a bent upright, how are you measuring all this by the way? I take it by KPI you mean king pin angle how did you work that out?

Stuart.

Link to post
Share on other sites
1 hour ago, stuart said:

Your camber still isnt right as it should be 0 so probably another shim in the lower inners would make that right (I did say start at 3) but that castor is way out, you need to check exactly what you have there as something is way out, it may well be you have a bent turret or incorrect trunnion or a bent upright, how are you measuring all this by the way? I take it by KPI you mean king pin angle how did you work that out?

Stuart.

Hi Stuart, yes I remember you said 3 but I only had 8 decent shims! 
Measuring for basic settings with below photo, I also have some turn plates for measuring rotation accurately for Castor/KPI. Seems to be pretty good but will obviously get full geometry checked when/if I get it close! 

Off to do some measurements on the NSF.

thanks again

Adrian 

F0D9EE07-522D-464E-B353-A8106C0B7102.jpeg

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.