kaiserbud

Still in the stages of checking out the car froim total rebuild.... I have 700 miles on it and today I noticed that the rear of the car seems to swerve or 'slide' to one side.

Issue:
When 'cruising' for a bit - say 30 seconds and you let off the gas, the rear end seems to slide to the left mostly. SOmetimes it seems to go right as well.. Often I hear 'clunking' in the rear end upon shifts only (like a U-joint) - not a grinding feel of needle bearings. The slide also happens on shifting up or down.

I realize it could be a U-Joint on the clunking, but I have had all rebuilt - even the trailing arms by a leading Corvette rebuilder. All Ujoiunts are new. Now the rearend is old, but proibably only has 20k miles on it. It is a 427 TH400 w373 gears. I grabbed the tires and pushed and pulled on them without any 'loose' feeling or noises. I checked up underneath and did not see any obvious loose issues.

There was a moment that I thought it could be the powersteering over-reacting from letting off the gas - but other than that - all seems to occur when shifting or feels like it is rear end related.

This morning was kind of a maiden voyage as I left the house at 5:30am to cruise the country and catch a sunrise... So limited on what I could do on teh trip, I will have to check out more tonight after work. Just looking for your thoughts.

It was 'scary' occurring at 15pmh, 35mph and maybe 45, but it could be a serious issue at higher speeds.

Thanks for the input.

billcarson

don't know about the clunking but your drifting sounds like rear wheel toe out. b t w my rear wheel u-joint had disintegrated needle bearings and never clunked.(only vibrated).have you read this? good luck.http://cmc.speeddirect.com/cs/blogs/...1963-1982.aspx

U17

Mine does that... I have new TA bushings and hope that fixes it...

ramair_bryan

That happened to me too on my 81. thought all kinds of money was gonna get spent. turns out the parking brake shoes were to tight on the right side, and putting a constant load on that wheel/tire. posi don't like that. And acted just like yours. Give it a look and I hope it's an easy fix after all. Lord knows we need them...........bryan in atwater ca.

kaiserbud

Bill - printing and reading now.

Bryan - My parking brake and parts are all new (w/trailing arm rebuild) - but I used teh park brake for the first time today and see where it needs to be adjustred tighter.

I got the offset trailing arms from Van Steel - very confident with their work and their end of the deal. Gee - those are a pain in the a$$ to remove - hope that is not the issue.

Its kinda like the car slushes around.

ramair_bryan

I supported the rear axles on stands, and fired it up. In gear i noticed one wheel stuck alot. Not good when you have a posi. So it would favor the other side on the road since it had instant responce from the throttle, the other didn't. ........bryan.

kaiserbud

Two more pieces of info....

The alignment was done by a reliable shop - they have done alignment work perfectly on this car for me in the past.

Also - brakes/calipers are all new. So is power steering pump, steering control assembly... but NOT my steering box. I only have 70k miles on it - so may get that adjusted if possible. I do have abit of steering wheel 'play'

Jim_Harrison

Lift the rear of the car off the ground and pull outward on the top of the tires. If you have excessive movement have someone move it while you look at the half shafts where they go into the diff. If the shaft is coming out of the diff, you have a broken retaining clip and this might be causing part of the problem.

Ron C!

Years ago, I had a 73 L82 coupe that developed a swaying to one side or the other while driving it. Anything over 35-40 was down right scary. I took it to my trusted alignment shop and they discovered that the rear spring center plate, the one the under the pumpkin that the strut rods connect to was loose. Some how, some way all 4 bolts had worked themselves loose. Tightened them up and the problem was cured. Worth a look.

kaiserbud

Thanks Jim and Ron. Will check when I get home...

Jim - on the retaining clip - thats on the inside of the pumpkin?

Belgian1979vette

kaiserbud

OK - I jacked up the car and pulled outwards on the top of the rear wheels. ALmost no play. The only play I had was on the left side and that was within the brake caliper/pad area - very minimal.

I noticed the right Offset Trailing arm is leaking grease a little.

I checked all the bolts - all tight, except the leaf spring plate. Those 4 bolts could have used a bit of tourqing. I guess they were at 45lbs +- I checked AIM and it said 65lbs, but I was hesitant to go over 62 based on the 'feel' of the tightening process. Especially one bolt felt like I could not go farther on the torque. The plate actually started to turn up on the corner lip a tad.

There were no marks on the crossmember that showed the rearend shifting. No marks on the leaf spring showing shifting.

Now I did notice/recall my issue about 4 years back when assembling my rear crossmember and bushings. The bushing really never seated fully in my opinion. I will have to search CF for the old post on that issue. Maybe that is it - the bushing are not fully in contact with each other.

kaiserbud

Hey guys... got to check this issue out.

Simple -Trailing Arm shims fell out on left side.

When the alignment was done, the left side was left a tad lose - so they fell out. Maybe a bit tongue in cheek, but I overlooked this because I just thought that would be too obvious.

Ironically, although I did not type it in my original posting, I compared this issue to losing the same feeling as when losing teh front A-Frame shims... should have listened to my instincts a bit more.

Thank you all for offering input.

Jharry pope

i had a similar issue with my 2000 vette. found out that the rear sway bar was broken but you couldnt tell by looking at it because it broke inside one of the bushings.

U17

After installing the new TA bushings mine drove like a real car again ....

jesse10886

My corvette was doing this too wich is why I am rebuilding te rear end with the polyurethane rebuild kit from corvette America I like this thread because I have a check list when I put it all back together also not to steal the thread but what is everyone's opinion on composite springs? I've seen 300lb,350,375 what would you guys recommend an do you suggest the composite spring is it a total replacement of the 5spring set up or just an added spring I want a comfortable ride (as comfy as I can with vette)

Mike Ward

Then why are you using poly?

wcsinx

Glad you found it. It's happened to many of us. "Crabbing" like you described is very often the result of worn TA bushings or missing alignment shims. Either can allow your rear toe to change suddenly and drastically with throttle on/off.

kaiserbud

Gents - appreciate the input... I have it re-aligned - but still feel a slight swerve... WIll investigate more soon and update.

Scottd

Well I know this will be a bit off topic but my 82 Camaro was doing the same thing. Come off the gas and it would pull quickly to one side. Now, switch to the next issue. I had a local shop install a set of 3.73's for me and after 2 years the rear end was making a hell of a whine. Took it to another shop and they had to rebuild it all. Turns out my diff was assembled so poorly that the posi was doing all sorts of crazy stuff. After the rebuild, he managed to drive straight.

Just some food for thought. If youve never had anyone in your pumkin messing with gears I wouldnt worry about it.