Rear end of the car shifts to the side under acceleration. Wtf??

[grantlacey11]

Hey guys,

Just replaced most of the rear end: shock mounts, springs, struts, sf + ta bushings, and a 4.10 LSD. Everything under there is good n tight, but when I'm cruising down the road (I can notice it more on the highway) and give it some gas, I can feel the rear of the car shift/step to the right, and when I let off the gas I can feel it step back the other way. This is something I have to correct with the steering wheel.

Could this mean a roasted diff? Anything else?

[///digitalme]

trailing arm bushings not tight???
i had something similar and tighten the trailing arm bushings and its good now

[grantlacey11]

I mean it could be...I had the car aligned ( I have an adjustable camber and toe sf) so im guessing they would have made sure of that...but it is worth checking

[Van Westervelt]

How are your subframe bushings? And your diff mount bushing? Those are the two thing that carry the whole year end. Everything you listed just puts it in a desired location, those two hold it there.

[grantlacey11]

Sf Bushings are brand new urethane. Diff bushing looks good.

[E30SPDFRK]

Does one of your rear tires need air? Same size tires left and right?

[ZM Blue Devil]

was the car in any sort of accident, had a similar problem recently, all parts were new, couldnt figure out, then came to find out the car had been in an accident and sure enough we measured the rear trailing arms and one had a slight bend. Swapped it out and straight as an arrow.

[BrewCity11]

Sounds like a toe problem. Could be front or rear actually.

[grantlacey11]

Does one of your rear tires need air? Same size tires left and right?

No just check air, bottlecaps all around!

[grantlacey11]

was the car in any sort of accident, had a similar problem recently, all parts were new, couldnt figure out, then came to find out the car had been in an accident and sure enough we measured the rear trailing arms and one had a slight bend. Swapped it out and straight as an arrow.

Car had been in one, but it was all front end, and I replaced everything up there myself all the way down to a new subframe...

[grantlacey11]

Sounds like a toe problem. Could be front or rear actually.

Now this sounds promising. Im going to try and call the place I got it done at to see if they can check it. Those rear eccentric bolt set ups aren't the greatest designs, maybe something shifted.

[grantlacey11]

Ok update:

Driving car today and letting off and on the accelerator abruptly, causing the car to do a quick lurch, I can hear a click/pop in the rear drivers side of the car. Im assuming this could be the toe adjustment bolts on that side have become loose, causing the trailing arm to move under load?

[CHIF8008]

make sure everything is tight under there

[JakeP]

No just checked air, bottlecaps all around!

I bought my car with bottlecaps all around. Looked at the tires and they were 3 different sizes.

If one rear tire is bigger than the other, it would cause this problem.

[BrewCity11]

Ok update:

Driving car today and letting off and on the accelerator abruptly, causing the car to do a quick lurch, I can hear a click/pop in the rear drivers side of the car. Im assuming this could be the toe adjustment bolts on that side have become loose, causing the trailing arm to move under load?

Yeah, if you have those adjustable toe/camber plates welded in back there, it would be ther first place i'd look.