Which diff oils do u recommend

[SAKO79]

I plan to change my rear diff oil and the dealer says 75W-85 synthetic. They also say I do not need no limited slip additive I have the g80 locking differential

 

The dealer here wants $21 a litre would you use the GM factory oil what would you use an aftermarket synthetic oil

[LongrangeLauber]

I use Mobil 1 75w-90 in this truck and the last. It's full syn. I use royal purple in my quad.

 

I would recommend Mobil 1 or Amsoil

[SAKO79]

Does the rear diff for front diff need limited slip additive

[SAKO79]

GM 75w85 is only a semi synthetic I'd rather put full synthetic in

[LongrangeLauber]

The Mobil 1 already has lsd additive in it, it won't hurt the differential if it's not required in the truck but it's already in the fluid

 

I believe I used regular dino oil in the front differential, and that's what GM recommends

[RyanbabZ71]

front diff 75W-90 in cold climates

 

No anti slip in either diff

[SAKO79]

K

[foo.c]

I haven't read the manual, but you might want to check if it has a recommendation for gear oil when towing. I think 75W-140 is the common suggestion.

[LongrangeLauber]

I haven't read the manual, but you might want to check if it has a recommendation for gear oil when towing. I think 75W-140 is the common suggestion.

I tow frequently and a high quality synthetic 75w90 is fine. I used 75w140 for break in of my other trucks diff after a rebuild

[SAKO79]

I just want to put a full synthetic and I looked up the g80 locker differential from eaton they recommend and say no friction modifier oil at all

[gone_fishing]

I have Amsoil Severe Gear 75W-90 in my rear dif. Plan on doing the front sometime soon.

[txab]

I have Amsoil Severe Gear 75W-90 in my rear dif. Plan on doing the front sometime soon.

 

 

+1

[Jimmy W]

Amsoil severe gear here also

[redwngr]

Does the rear diff for front diff need limited slip additive

No.

[Black02Silverado]

AMSOIL Severe gear 75w-90 in both will work well. It has been in both of mine since 10k miles and I'm at 156k now. All is well.