I have a 2002 Dodge RAM 1500 4.7L V8 4X4. The book calls for 75W90 GL-5 gear lube in both rear & front with 5oz of LSD additive in the rear. I am replacing the fluid this weekend in both differentials and thought I would switch to 75W90 Synthetic gear lube. The brand I am planning to go with is the Advance Auto brand. Anyone have thoughts or concerns about using that brand? The price was much better than all the other brands and I though synthetic would be much better.

 

I use Royal Purple regular synthetic in the front. 75w90. I also use Royal Purple synthetic in the rear..cant remember if its 55w140 or 75w140.....Dont need to add the additive if you use Royal Purple.

 

I use RP as well. Agree no additive needed for LSD if using RP. I know nothing about Advance Auto brand.