Rear Diff fluid specifics?

[MarksmanAkula]

I serviced my rear diff a few months back, and at the time realized i had put in the wrong fluid. Manual called for 80-90, and i accidentally read the part where it called for 75-140.

I've read on here guys like dino 80-90, could i get a link to the specific stuff you guys use?

I believe i have an open rear end, when i spin one tire the other rotates the other way.

 

[tommudd]

75-140 will not hurt a thing, that is what I run in all 3 of mine, have for the last 15 years
dino of course

 

[MarksmanAkula]

75-140 will not hurt a thing, that is what I run in all 3 of mine, have for the last 15 years
dino of course

thats the thing, i didn't put in dino, it was synthetic.

Could you send me a link to what you use? It'd be greatly appreciated!

 

[kejobe]

I use Valvoline 75-140 synthetic with friction modifier in the rear (I have LSD) and put Mobil 80-90 synthetic in the front. No issues with either.

 

[uss2defiant]

aren't all dino gear oils that's GL-5 rated about the same?

 

[Big Al]

My manual says use 75-140 if your towing and the regular 80-90 if your not.
Sounds like 75-140 will take more pressure and will not see metal to metal contact like 80-90 would see when towing.