I have screwed up my own Gov Lock with friction modifier.... some GM dealers are so dumb they still add it...... and wonder why the customers bitch their G80 doesn't work. Straight 75W90 or 80W90 gear oil works great. I use Amsoil Severe Gear 75W90. Although compatible with limited slip they do recommend adding their friction modifier to keep clutches from chattering.

 

 

An Escalade and a Volt..... hahahahaha. That's awesome!

 

Ha I know right. The Escalade actually replaces a TDI Jetta that we just turned back into VW yesterday. Grew up in a GM household (dad was an engineer at Cadillac and Chevy) so it's nice being back in a familiar vehicle. .