TR6 Uneven rear suspension

[pdplot]

Despite some work done, my '71 TR6 still is about 1.5 inches lower on the driver's side. What's the easiest way to fix it? 1. Switch the rear springs left to right, etc. or shim the left side with a spacer? Or - is there another fix that won't involve major work? The car has about 102K or so. How long should a coil spring last with its original elasticity?

 

[Gliderman8]

I had a similar problem with my TR6 when I was restoring it. I tried new springs but that did not improve the situation much. I had an aluminum spacer made to fit the top of the spring and that made all the difference. Is it major work? Well, you have to remove and reinstall the spring which is not fun and as you know can be dangerous.

 

[JerryVV]

There are several things that could cause this and without knowing what work has been done it's hard to answer your question. I'd be looking for the real reason and not just assume it's the spring. Is the frame cracked, is the Trailing Arm bent or cracked? Is there something wrong with the TA Mounts. Is the top spring mount weak, bent or cracked?
Did you compare the rear springs and are they the same length?

 

[pdplot]

Answer - no on all counts. In the Spring (no pun intended) I'll drop the arms, remove the springs and compare them. It would stand to reason that the drivers side would be lower after many miles - just like the seats. The only work done to the rear suspension was to replace a bent trailing arm on the right side with new bushings also. It was even lower before the work was done. The rear suspension doesn't have much "give" anyway. Suspension travel is limited.

 

[mallard]

How was the trailing arm bent? Could the frame be bent? I would check the frame where the arm connects. Could you have mounted the brackets upside down?

 

[JerryVV]

Well it does not stand to reason that the spring would be shorter just due to age. It could be but in the 40+ years of ownership my TR4A IRS rear springs were exactly the same length when I replaced them with Goodparts shorter springs. What stands to reason is that there could be something other than the spring sagging that may contribute to one side being lower than the other. But if you want to only focus on the spring why did you ask for someone's help? Best of luck.

 

[pdplot]

Right arm got bent when right rear wheel came off. Wire wheel hub nuts got loose because I failed to torque them down enough. Lesson learned the hard way. I crossed the road (lucky for me nobody was coming down that usually busy road) spun around and hit the curb with the right rear axle & drum. I drove it that way for over two years never realizing it was bent. My expert friend had a spare - we pulled off the bent arm, replaced it with his arm and new bushings and placed some shims on the bracket after he ran a piece of string from the rear wheel to the front of the car and found it was off by several inches. I never realized why my steering wheel was not in the straight ahead position when the wheels were straight. It's still a tad off - perhaps needing one more shim. If your TR6, TR4 IRS or TR250 steering wheel isn't straight, don't pull off the steering wheel until you check the rear suspension toe-outwith a piece of string. The left wheel is straight. How do you know if your frame is bent? It looks ok. I guess I could measure ground to frame on each side when car is on level ground. I'll let you know my findings.

 

[JerryVV]

I think your answer lies in the results of the spin and the impact on the right side. If it was hard enough to bend the TA, it was hard enough to bend other components as well. Have your frame evaluated by a body shop that has a frame machine. Frame dimensions are available in several of the repair manuals. And have a professional do an alignment. By the way the rear has toe in not toe out and if off by several inches, that should be a clue as well. A good replacement TA would not be off by several inches requiring additional shims. My guess is that the frame is also bent.

 

[skikir]

Man I'm in the exact same boat! When I got my TR6 there were none to found and bought one that had been in an accident. Supposedly it had been side swiped by a semi on the Left side. When I got it together it would not drive straight with out massive shimming in the rear and the front left sits low. Found the frame bent. Got the frame straightened, no change. Argued with the frame shop, no change. Found excellent replacement frame. When I had the old and new frame out I compared them and measured and could not see any difference. I traced them both out on a big piece of card board and could not see any difference. Scratched head. While the car was up on jacks putting the rear rear wheels on I noticed the rear wheel vertical angles were way off. I don't know how many times I've had it up on jacks and never noticed it but I guess I was just at the right angle. Pulled out the trailing arms and looked at them. The Right trailing arm was bent at the joints. Got replacement arms. Car now runs straight with equal shims BUT Left front STILL sits low. Last weekend I pulled front springs out, looks good. General inspection of parts, nothing seems bent. Replaced lower left spring pad with up rated 3/8" thick urethane lower spring pad. Still low. Need to check Right rear spring pads. I have a Rouge thick spring pad laying around (where did that come from?) Maybe I didn't notice I have thick spring pads in the Right Rear pushing the Left Front Down. The difference between the Left and Right Front is a little finger with a corresponding difference in the rear. Makes the driver look like he weighs 400 lbs and I don't **** it!

As a side bar. I got the trailing arms from another guy who I sold my old rusted parts car to. I thought I was buying my old trailing arms back but he said that my old trailing arms were cracked and he threw them out. I actually got another pair which supposedly came from an undamaged car. So, although the trailing arms may look beefy they may actually be rather weak. Plus with their odd shape it is hard to tell if they are bent.