Hello all... I read somewhere that multivelocity oil should not be used in the rear diff. Others say its okay. The manual says straight 90 weight. All I can find in the store is 80w90 --- When I ask the dealer I get different answers from different people working there. Am I lost? Yes Am I frustrated with this topic... yes!

SO--- I want to know what you guys are putting in your trucks rear diff.

 

I use 80w90 and have never had any problems. I always change it too when I run through deep water that covers the axle even though I have diff breathers just to be on the safe side.

 

you're not going to have a problem with regular old 80w90.

 

i every vehicle I've changed diff oil in everytime I went to the auto store all I've been able to find is 80w90 usually Valvoline....I never had any problems.....

 

I use Mobil 1 75w90, front and rear.

 

80w90 for me also. Just changed it out about a week ago. The front diff had thick gooy sludge and I'm guessing that it may not have been changed for a long, long time.

 

80w-90 Valvoline in my trans and rear diff....made shifting a lot smoother too.

 

Great, I'll go w/ 80W-90 in the rear... how many of you perfer syn over conventional?

 

I use amsoil 80-90w

 

I just did mine today and I used 75-90W Valvoline synthetic oil. Check this thread.

George