Expert: Brad Sears - 4/3/2008

Question
I recently purchased a 1973 camaro LT with the original rear end (posi option) and while driving it home (over 2600Km travel distance) the rear end started making noise and acting up. It only happens when starting from a prone position and especially acts up when turning corners and at low speeds. The best I can describe it is a sort of stutter. Initially, I thought that the brakes may be seizing, but after a short mechanic stop(didnt have time for a full inspection) the brakes were found to have no problems. I was hoping you might help me to diagnose this problem as I'd rather not buy say a new rear end and find out it was the driveshaft causing all the problems. Advice as to tests one could do at home or anything to look for would be greatly appreciated. Thanks, Alex

Answer
Check with your local GM dealer and buy the rear end fluid they sell for the Posi. Change the fluid and it should work.
Brad
This was a well known problem back in the 60' and 70's. GM spent as lot of time and money publishing tech service bulitens to their dealers on the subject. The locking differentials used a clutch system that when hot with the wrong gear lube would cause the clutch plates to stick and slip, stick and slip and cause the problem that you are describing. If you do not want the advice why did you ask.