Boxing in the front diff mounts

[foster461]

I have my diff out for a refurb and while that is being done I'm cleaning up the chassis at the rear. I thought the diff mounts looked ok until I started removing the rust and I find that the right hand mount (passenger side, LHD)has a hairline crack close to the stud. I plan to grind that out and weld it and to add a bit more strength box in the brackets. Welding the inner plates will be no problem but I wonder how to tackle the outer plates ?. It looks like I might be able to get to it though the bracket from the inside, ie do the outer plate before the inner. I wonder if anyone has done this and has any advice to offer ?

 

Stan

[Tom Fremont]

Stan,

 

Good luck with the beefing up - I had it done on mine with the body off so I don't really know how you should proceed. I also needed to reinforce the spring outriggers, as one cracked and sprang up into the air once the body was removed! You can go a good bit further than the kits currently available...

[RobIsaacson]

I thought that as well while I had my diff out last year.

I just boxed the inner ones and left the outers as they were. I figured it would be beneficial to at least do something while I was there.

Depends on how much trouble you wish to go to I guess.

Regards

Rob

[Richard Crawley]

Stan

It’s not that easy to make a decent repair with the body in place; I did mine on a bare chassis during the resto. Others have carried out repairs by either jacking just the rear of the body or cutting access holes in the floor pan & welding from inside the car.

 

I didn’t even know I had a problem until I got the body off, it all looked fine from underneath with everything in place but it turned out to be a complete mess! The front mounts & cross member seem to suffer by far the worse & I had to cut out & completely re-fabricate the brackets, boxing in both sides; I cut off the corner of each plate at 45 degrees, leaving a small hole in each corner; this helps to avoid trapped water & helps relieve stress the chassis members where the corners meet; all the pins were shot & I had to replace them.

 

Other things to look for; as well as breaking out of the cross members, the pins wear & many are also bent! Cracks can develop in the front cruciform chassis member (that one with the spring mounts); I had two, two inch cracks extending radially from the tops of the pins on my car which I had grind out & weld up; almost impossible to see or repair from below!

[foster461]

Stan

It's not that easy to make a decent repair with the body in place; I did mine on a bare chassis during the resto. Others have carried out repairs by either jacking just the rear of the body or cutting access holes in the floor pan & welding from inside the car.

 

I didn't even know I had a problem until I got the body off, it all looked fine from underneath with everything in place but it turned out to be a complete mess! The front mounts & cross member seem to suffer by far the worse & I had to cut out & completely re-fabricate the brackets, boxing in both sides; I cut off the corner of each plate at 45 degrees, leaving a small hole in each corner; this helps to avoid trapped water & helps relieve stress the chassis members where the corners meet; all the pins were shot & I had to replace them.

 

Other things to look for; as well as breaking out of the cross members, the pins wear & many are also bent! Cracks can develop in the front cruciform chassis member (that one with the spring mounts); I had two, two inch cracks extending radially from the tops of the pins on my car which I had grind out & weld up; almost impossible to see or repair from below!

 

Man, I hope my frame is not quite that far gone.. it really does look very solid other than the crack on the RHS bracket and in reality I'm just not mentally prepared to take the body off, at least not this winter and before I have expanded the garage or built a barn.. Of course if further investigation reveals that the studs are breaking out of the top then its all over for 2007 and probably 2008 and I can make the case to buy another TR to use in the interim !.

 

I think for now I'm going to fix the crack and install some plates on the inner side of the brackets and hope that holds me for a while until I am ready to face the seperation of the body from the frame.

 

Stan

[Tom Fremont]

I don't know about the RoW cars, but in the US one of the most popular tricks to perform on the TR6 was to " get rubber " in the gears; i.e. make the tyres chirp when shifting. It was possible in some cases to achieve this in 3rd gear ( as a perpetrator I can vouch for this personally ). The price for this behaviour is rather clear now .

 

I would venture to say that most of the U.S. cars were subjected to this - so if you get your hands on one of these don't be surprised if this area needs attention...

[foster461]

I don't know about the RoW cars, but in the US one of the most popular tricks to perform on the TR6 was to " get rubber " in the gears; i.e. make the tyres chirp when shifting. It was possible in some cases to achieve this in 3rd gear ( as a perpetrator I can vouch for this personally ). The price for this behaviour is rather clear now .

 

I would venture to say that most of the U.S. cars were subjected to this - so if you get your hands on one of these don't be surprised if this area needs attention...

 

 

eek. I imagine the only chirping you would hear would be the sound of bits broken diff mounts grating against each other.

[Richard Crawley]

I don't know about the RoW cars, but in the US one of the most popular tricks to perform on the TR6 was to " get rubber " in the gears; i.e. make the tyres chirp when shifting. It was possible in some cases to achieve this in 3rd gear ( as a perpetrator I can vouch for this personally ). The price for this behaviour is rather clear now .

 

I must admit that regularly dumping the clutch on 'burn outs' away from traffic lights back in the 70's/80’s was almost certainly how mine got damaged so badly; oh the foolishness of youth! I’d probably get arrested if I did it now.

[foster461]

Stan

Others have carried out repairs by either jacking just the rear of the body or cutting access holes in the floor pan & welding from inside the car.

 

I'd like to learn more about what is involved with raising the rear of the body off the frame, that sounds like something I could achieve even with my limited space. I imagine that all the body bolts and perhaps some wiring and tubing etc might have to be removed. If anyone has any insight into how that works I would be very interested.

 

Stan

[Richard Crawley]

Stan

I have only removed the body as part of a total strip down so don’t know how high you have to jack for suitable access & you may have to take precautions to avoid damaging the front end beyond a certain point. Personally I would jack it up square or you should be able to lift it fairly easily with a helper on each corner – I regularly shifted mine around like this! Others who have specifically done it without stripping down may be able to give more of an insight but from memory you need to:

 

1. remove all of the body mounting bolts, including one in the boot tyre well

2. fuel lines to the tank & where they transfer to the body in the engine bay

3. hydraulic lines at the front where they transfer from chassis to body

4. overdrive electrics if you have one - the main wiring should be OK as it’s all be inside the car

5. battery, starter motor & alternator cables

6. spedo & rev counter drive cables

7. steering bar at the rack

8. heater pipework

9. handbrake cables

10. you may also have to remove some bits in the engine bay to allow the body to clear – PI/carbs, radiator &/or cowl

11. It’s essential you brace the tub across the doors before you jack or you may end up with it bent in half!

 

It sounds like a lot of work but probably not as daunting as it seems but it’s definitely not something to attempt on a Sunday morning before dinner! Can’t guarantee I haven’t overlooked anything!

[foster461]

Stan

I have only removed the body as part of a total strip down so don't know how high you have to jack for suitable access & you may have to take precautions to avoid damaging the front end beyond a certain point. Personally I would jack it up square or you should be able to lift it fairly easily with a helper on each corner – I regularly shifted mine around like this! Others who have specifically done it without stripping down may be able to give more of an insight but from memory you need to:

 

1. remove all of the body mounting bolts, including one in the boot tyre well

2. fuel lines to the tank & where they transfer to the body in the engine bay

3. hydraulic lines at the front where they transfer from chassis to body

4. overdrive electrics if you have one - the main wiring should be OK as it's all be inside the car

5. battery, starter motor & alternator cables

6. spedo & rev counter drive cables

7. steering bar at the rack

8. heater pipework

9. handbrake cables

10. you may also have to remove some bits in the engine bay to allow the body to clear – PI/carbs, radiator &/or cowl

11. It's essential you brace the tub across the doors before you jack or you may end up with it bent in half!

 

It sounds like a lot of work but probably not as daunting as it seems but it's definitely not something to attempt on a Sunday morning before dinner! Can't guarantee I haven't overlooked anything!

 

Thanks Richard, I agree it sounds time consuming but do-able. I'm not prepared to do it this winter so I think I will effect the immediate repairs and think about this for next winter. I had planned to pull the engine out next year so I could re-furb it and the under bonnet area so this would just be an escalation of that project and may bleed into spring/summer of 2008 but it would be a chance to get at the whole frame and fix any remining issues with the diff mounts. I could build some trestles that would straddle the chassis and hold the body off the frame by a couple of feet and host a tub lifting party..

 

Stan

[Richard Crawley]

I could build some trestles that would straddle the chassis and hold the body off the frame by a couple of feet and host a tub lifting party..

 

Stan

 

I rebuilt my car in a single garage (or mostly outside it) & that's exactly the method I used to build up the refurbished tub & spray it inside & out. I first repaired, sprayed & built up the chassis as a complete rolling unit, wrapped everything in heavy gauge polythene & bolted some plywood to the top, two timber trestles were made so they would support the body either way up & just sat on top of the plywood; a sort of large mobile work bench.

[foster461]

The rear end plot thickens.. still havenet repaired that crack yet but while I'm getting ready to do that I've been cleaning up the frame and generally checking things out. I pulled the lhs axle out so that I had unobstructed access to that area of the frame (the diff is out so pulling the axle out was no big deal) and now that I have it on the bench I can feel a "notch" when I rotate the hub. There is no obvious play, up or down, in or out but when I turn the center rotating part of the hub it stops at one point in the rotation and needs a bit of a nudge to overcome the resistance. If I were designing it to do that I would have a hole and a spring loaded bearing to drop into it..

 

I'm guessing this isnt normal but I dont recall this symptom being a traditional failure mode for the hubs.

 

Comments ?

 

Stan

[Richard Crawley]

Stan

If it ocurs in the same place every revolution, have you checked for any obvious fouling on external parts – locknut, tab washer; & check the rear stone guard is not dented/bent & fouling on the rear of the casting; it could be a seal problem but you can’t inspect/change them without a strip down. If could be something in the hub grease that’s worked its way into a bearing track, have you tried turning it for a while to see if it disappears. The gloomiest scenario is that one of the bearings is damaged but this is unusual as they mostly develop excessive play! Difficult to give advice without having a ‘feel’ but if it wasn’t noisy before removal you could refit & monitor it closely I suppose; otherwise it sound’s like it may be hub recon time &, as you’ve probably read, best of luck with that one! I’ve only ever managed to get one apart but Ron has the mother of a puller that seems to work quiet well!

[Guest ron]

Stan

Like others I did the repair when the body was off, but I think if I was in your position I would be inclined to cut a piece out of the rear cockpit panel to do weld repairs from above as well and then patch the panel, I know it sounds a bit of a botch but the damage to mine would have been very difficult to repair longterm only welding from below.

The advantage of getting access to the top of the crossmember is you can weld in a new pin properly and weld on a large reinforcing patch on top of the crossmember, then box in the pin mount from below, if I can find some pics I'll post them later.

Ron

[RogerH]

Hi Stan,

when I carried out my rebuild from my single garage and driveway I made sort of gantry that sat on wheels so that the body could be lifted off the rolling chassis and then either the chassis or body rolled out onto the driveway.

The gantry was fairly crude but effective. I used 4 x 3" x 6ft fence posts for the corners and 8ft x 4"x2" down each side and something similar across the car, back and front. 2 scaffold poles (one at front of gantry and one at the back) with handles welded on. Ropes slung from the poles through the body. Then by rotating the poles the body raises up - magic!!

The 4 corner posts each have a castored wheel attached.

By getting the dimensions right the whole thing can live quite happily in the garage during the work. It is a one man job to lift the body off and put it back.

 

Roger

[foster461]

Stan

If it ocurs in the same place every revolution, have you checked for any obvious fouling on external parts – locknut, tab washer; & check the rear stone guard is not dented/bent & fouling on the rear of the casting; it could be a seal problem but you can't inspect/change them without a strip down. If could be something in the hub grease that's worked its way into a bearing track, have you tried turning it for a while to see if it disappears. The gloomiest scenario is that one of the bearings is damaged but this is unusual as they mostly develop excessive play! Difficult to give advice without having a 'feel' but if it wasn't noisy before removal you could refit & monitor it closely I suppose; otherwise it sound's like it may be hub recon time &, as you've probably read, best of luck with that one! I've only ever managed to get one apart but Ron has the mother of a puller that seems to work quiet well!

 

I didnt see any obvious exterior interference and the lumpiness feels internal. I'm not going to mess with it myself, the rebuilt units are not that expesnsive (around $250 per side, exchange, including new UJ and wheel studs) so I think I'll go shopping just in case.

 

Thanks.

 

Stan

[foster461]

Stan

Like others I did the repair when the body was off, but I think if I was in your position I would be inclined to cut a piece out of the rear cockpit panel to do weld repairs from above as well and then patch the panel, I know it sounds a bit of a botch but the damage to mine would have been very difficult to repair longterm only welding from below.

The advantage of getting access to the top of the crossmember is you can weld in a new pin properly and weld on a large reinforcing patch on top of the crossmember, then box in the pin mount from below, if I can find some pics I'll post them later.

Ron

 

 

Thanks Ron. I think if my assesment was that pin failure was imminent I would take it off the road and lift the tub and do this job and any other frame work at the same time. I'm really hoping that given the overall condition of the frame that the current failure is confined to that one bracket and after welding that crack and partially boxing in the brackets I will be good for this season and ponder the bigger project for next winter.

 

Stan

[foster461]

Hi Stan,

when I carried out my rebuild from my single garage and driveway I made sort of gantry that sat on wheels so that the body could be lifted off the rolling chassis and then either the chassis or body rolled out onto the driveway.

The gantry was fairly crude but effective. I used 4 x 3" x 6ft fence posts for the corners and 8ft x 4"x2" down each side and something similar across the car, back and front. 2 scaffold poles (one at front of gantry and one at the back) with handles welded on. Ropes slung from the poles through the body. Then by rotating the poles the body raises up - magic!!

The 4 corner posts each have a castored wheel attached.

By getting the dimensions right the whole thing can live quite happily in the garage during the work. It is a one man job to lift the body off and put it back.

 

Roger

 

Roger, amazing. It sounds like you could storm a castle with a contraption like that :-) did you take any pictures by any chance ?

[Canadian TR]

Stan,

I just had both my diff mounts boxed in both sides with the body on. I started to do it myself but decided it was beyond my welding expertise so I asked a friend with 30 plus years as a welder to help. His method on the outer plates was to weld blind by feel. So yes it is possible to weld with the body on . It depends on the welder.

Andy

[Guest ron]

 

 

Hi Stan, on the first photo you can see from the heat marks the size of the plate that was used to reinforce the crossmember, I think this problem with the diff mountings is more complicated than a straightforward crack I think there ia also a lot of stress corrosion cracking in the metal surrounding the pin, hence the need for reinforcement.

Ron

[foster461]

Ron, looks like you, or someone, did a pretty nice job with that bracket. Its hard to tell from the photo but it looks like you built in some holes for ventilation and drainage from the boxed in bracket too. Certainly would be a lot easier with the frame upside down on the floor than right side up with the body on. I was quite inspired by the earlier post from Roger. I'm going to give that some serious thought for next winter.

 

Stan

[Guest ron]

Stan

I can modestly claim it was all my own work

It's actually quite easy on a bare chassis, I find welding chassis thickness metal very easy compared to body thickness [presumably so do most folk] that's why if your chassis is otherwise sound I would have no hesitation in cutting the rear cockpit panels to enable a similar repair which would be permanent rather than a stop gap.

Ron

[Richard Crawley]

Here’s some more pics to looks at; not digital so quality not as good. Again you can see the outline of the backing plates used on the front mounts; I fitted mine to the underside rather than the top & they look slightly bigger than Ron’s. You can’t really see it in the pics. but, as I said in my previous post, I also cropped the corners of each plate to leave a small hole in the corners, mainly to avoid stress concentration but also to prevent any chance of moisture getting trapped; you can also just see the end result of the new trailing arm chassis sections & breast plates after welding up.

 

 

Opps one seems to be upside down!

Edited January 19, 2007 by Richard Crawley

[foster461]

Here's some more pics to looks at; not digital so quality not as good. Again you can see the outline of the backing plates used on the front mounts; I fitted mine to the underside rather than the top & they look slightly bigger than Ron's. You can't really see it in the pics. but, as I said in my previous post, I also cropped the corners of each plate to leave a small hole in the corners, mainly to avoid stress concentration but also to prevent any chance of moisture getting trapped; you can also just see the end result of the new trailing arm chassis sections & breast plates after welding up.

 

 

Looks like you had to do quite a bit of restoration on that frame Richard. Its amazing that they all fall apart aft of the T-shirt while the rest of the frame survives quite well even though the whole thing was just blown over with some black paint at the factory 30+ years ago.

 

Stan