Going to change my rear Diff oil this w/e, I already bought the recommended additive from GM, not sure which weight royal purple I should run, and does anyone how much it holds.
Thanks in advance

 

First, I would recommend you use the regular GM gear oil, but if you're going to use Royal Purple, I'd get the 75W90 or 80W90 depending on how much abuse your rear sees. If you go to the drag strip a lot, I'd use the 80W90. It will take slightly less than two bottles (2 quarts).

 

DONT buy royal purple, everybody that I've talked to that has NEVER used it says it works great, every body that I know that races say's they've blown **** up w/ royal purple, I've seen it happen, I would get the gm gear oil if I were you, and for any additives lucas IS the best!.... happy fluid changeing....

 

Thanks for the input guys, Im probably gonna just stick with the GM gear oil then.

 

Redline makes great stuff. All that DTE in Indiana uses. Good enough for them, good enough for me!

 

what about Mobil ! gear oils

 

Another vote for the Redline gear oil.

 

what weight 75w90

 

Yes 75w90 with the limited-slip friction modifier.

 

I agree....

 

just use teh GM stuff your not gonna see much of a gain. Synthetic gear oils from what I understand do not work well with our rears. But i honestly do not know. But since I blew my rear end sky high recently I will be adding some gear oil myself ANd a new rear end