Engine/Transmission (1998.5 - 2002) What rear diff lube?

[DWest]

Am going to our mans mall called Fleet Farm to get Amsoil gear lube, what weight do I need and how much? It's a 3/4 ton with LS clutches.

 

[JKinney]

75-140 amsoil severe gear lube 5 quarts

 

[Chief USA]

If you are going to be doing extended and or heavy towing, as JKinney posted, the 75W-140 is the way to go.



I tow occasionally so I went with the 75W-90. I have checked the diffs immediately upon stopping while pulling heavy (at least for me) a 12,000 lb. load of firewood and the rear diff was merely warm to the touch but not hot.