Cadillac SRX First Generation Forum - 2004 - 2009 Discussion, 2006 3.6 awd front and rear diff and transfer case fluid change in Cadillac SRX Forums; Any particular kind I should get what additives and how much of each. Going to let the dealer do the ...
Automobile(s): Cadillac '07 SRX-V6 RWD, '03 Envoy, '95 S10 pu
Gold Canyon & Happy Jack, AZ
Re: 2006 3.6 awd front and rear diff and transfer case fluid change
Of course the place to start is what's recommended in the owner's manual. With that said you'll find it difficult to find aftermarket gear oils that say they meet the GM specs shown in the manual. My 07's differential fluid was changed when the recall on the pinion seal was done. The p/n for the gear oil was 89021677. Plus since I have the limited slip axle (aka G80 RPO) the friction modifier, p/n 1052358 was added. I don't think the friction modifier would be needed if you don't have the G80 option. Certainly not in the front axle. I'm using Royal Purple gear oil in my 03 Envoy however the price has increased over the years that it isn't that much cheaper than the GM spec stuff (which is around $30/litre). Many on the Envoy forum use Mobil 1 75w-90 synthetic without issues however the Envoy uses an American Standard differential, I think our SRX axle is manf. by Getrag... if that makes a difference!
This really doesn't answer your question..... probably if you use a brand name 75w-90 synthetic gear oil it will last the life of the vehicle. Maybe you can get the dealer to give you a discount on the GM stuff since they are doing your transmission.