go to a GM dealer and they have a limited slip additive that you add to your rear end fluid.
75w140 synthetic with limited slip additive.
Nothing, Posi-Track is a brand name (GM), limited slip is what it is. Kind of like Kleenex is to facial tissue.
The rear axle is a "live-axle", one solid axle connecting to the differential in the middle of the vehicle.
Ford Mustang was very popular, Corvettes, VW bugs and vans, Chevy Belaire, Buick Electra, and many more others.
ChecksIf it is a front wheel drive car, better check the wheel bearings, they sound kind of dry and you don't want them coming loose while driveing, ,,if it is a rear wheel drive, you might check the wheel bearings and check the differential and make sure it has differential oil in it
Differential medium.
It uses 75W90
The 2006 Buick LaCrosse has a 4-speed automatic.
The 2009 Buick LaCrosse has a 4-speed automatic.
The 2002 Buick Regal has a 4-speed automatic.
The 2004 Buick Regal has a 4-speed automatic.
The 2014 Buick Regal has a 6-speed automatic.