MN81C3

I recently had new BFG’s installed on my 81. What I immediately noticed is that on acceleration the rear end will shift to the right and when I get off the throttle it shifts to the right. The old tires were quite old and near bald so it may have been doing all the while but to a lesser extent. I had a 4 wheel alignment done, no problems we noted other that out of alignment. It tracks straight while cruising steady. Any ideas?

SH-60B

Maybe the differential crossmember loose?

wfo76

Also general symptoms of just everything worn out.
Are the rear suspension parts original? How many miles?
Trailing arm bushings, worn side yokes causing camber change, spindle bearings out of spec, etc. could all cause this.

BKbroiler

That could also be a problem in your positraction unit.

MN81C3

Thanks Guys. I had the Rear End Rebuilt Last summer ('07), lowered gears and a new Posi Unit was put in. At the time they said the trailing arms were showing normal wear but were not bad. I will check to be sure everything is tight as it seems to happened over night.

Next step sounds like trailing arm rebuild. Heck - it's just money right!

Van Steel

bad t-arm bushings. also check that the shims are in place after the alignment.

Ironcross

..

Check your tire pressure, ...

thegazman

My 79 had a similar problem. The stub axle retainer was missing inside the differential allowing the axle to move out during acceleration.

427V8

also check alignment, camber and toe. your thrust line needs to be dead center.

If you have loose or worn components your thrust line will change causing the problem.

My car will go straight as an arrow both tires spinning as long as I want.

gingerbreadman1977

my car also shifts under accellaration from the lights. but its not just right. its left , right . left with copious amounts of smoke coming from the back.

FB007

Rear toe in is wrong. Take it back.

0Willcox Corvette

I think all above are great suggestions.

A car that feels like it is steering from the rear is usually the front trailing arm moving. Either you have shims that have fallen out, or bad front bushings.

One time in our shop we had a car where someone had tried to repair a rusted trailing arm with a metal plate. The welds rusted out and the arm was ready to break in half.

Alignment could cause this, bad strut rod bushings, snap ring missing from the rear end yoke, bad front bushings, trailing arm front shims missing.

For a car to drive from the rear something in the rear end has to be moving.

Check all of these things and you should find your problem.

Willcox

MN81C3

Thanks for all the info. I am bringing it into a Corvette Shop in the area this week. I will post the results.

Thanks again.

0Willcox Corvette

Before you give the shop the go head to repair, have them show you the problem and then post the results. You know what to look for now so you buffalo-ization should not be a problem. Let’s hope its just an alignment issue.

If they are a reputable shop they should be able to figure this out.

Willcox

OMF

You have to wonder if the tire shop damaged something while lifting the car since it was noticable right after the new tires went on...............

MN81C3

I brought the car into the shop over the weekend. We put it on the rack and looked it over. The Drivers side look ok but the mechanic pointed out that the passenger side looked to be shifted. He pulled it apart yesterday and found that the pass side trailing arm was bent and had been shimmed in an effort to correct it. The Drivers side had been replaced and everything looked good - but the pass side was original. Why the previous owner only did one is beyond me. He is going to replace the pass side trailing arm, bushings, etc.

While I was there - he did point out the front A arm bushings were shot and the passenger side lower A Arm was also bent. He said it looked like someone slid sideways into a curb or something causing the passenger side suspension damage. He said to bring it back just before the snow fly’s to correct it and gave me the option of replacing the all four a-arms with the tubular type with Poly. Sounds like the way to go.

Should get it back this weekend.