|
This has always been a problem with GM and limited slip differential (posi). They use cheap low bidder gear lubes. Get ride of the GM stuff and use AMSOIL, Red Line or Royal Purple synthetic 75W-90 gear lube.
My new 2009 CTS had the have the gear lube replaced and additive used before I had 500 miles on the car. Less the 500 miles later you could hear the clutches grabbing/releasing on turns and sometimes a banging noise when slowign down. I insisted they install AMSOIL Severe Gear 75W-90 instead of GM crap and to this day, 3.5 yrs later I have not heard one noise from my rear axle. Factory fill lubes a low bid. If you continue to use the GM lube you will continue to have this problem. GM is stuborn, they will never recommend any lube that does not make them money.
PS - Way back in 1970 my new Chevelle SS454 did the very same thing and they changed the lube so many times that they refused to do it again and I had to live with it.
|