Hi,
I recently purchased a 2002, standard shift with 9,800 miles on it and I have a problem with the rear swaying to the right under somewhat heavy accelleration. On a number of occasions now, I have taken the car to 65 to 85 MPH in 2 and 3rd gear and the rear end would suddenly kick to the right very quickly and then sway left in line again. The tires are NOT breaking loose. A corvette shop in the area suggested having the alignment checked, which I did and it was fine and all suspension components/nuts and bolts were tight. Under normal driving conditions the car is fine. The car is out of warrenty, but I knew that when I bought it. I can only guess that something in the posi unit may be malfunctioning under acceleration. Clutches slipping or something of that nature. Has anyone out there ever encountered anything like this??? The traction selector is set to the correct setting. I know that the guy I bought the car from played wit this button because he commented about the "Competitive Driving Mode" What exactly does that mean? It is not set in that mode now. Would the posi unit need to possbily be reset electronically somehow? Please let me know if anyone has encountered this situation before and if you have some advice on what to have checked. I am going to have the fluid level checked over the weekend. How often should this fluid be changed. Would any lack of the posi additive by the factory cause this?
Thanks a lot for your help.

 

Had that problem with my 84 vette and it ended up being the rear control arm bushings wore out.

 

I doubt that it is the "posi". It appears that you have something worn in the suspension. Stepping on it hard, letting off and stepping on it hard will make the car turn one way or another as the rear axles move lateraly. If the wheels were spinning and the posi was grabbing that would be a different story. I would check all the places where the a-arms attach and the other points that tie the rear end, axle assembly to the car.

 

Describe exactly what you are doing and sensing and what settings you have the AH/TC set in.

Under hard acceleration AH will sense swaying of the car as the rear tires slip slightly and it will apply the brakes on the correct wheel to bring the car back into line. This is especially true if you are accelerating off a corner. The rear end will kick back and forth to keep you in line with the direction you are steering.

Bill

 

If your problem is happening during a hard shift, I'd suggest replacing the rear shocks. I had the same problem on any shift in the higher RPMs, and a set of Z06 shocks put an end to that.

My car was almost un-predictable whenever I'd bang 2nd gear, merely from the swaying I would get.