What type of oil do you use on the Detroit locker end, thanks
Tor
Does not take anything special. it has no clutches to worry about.
https://www.eaton.com/Eaton/ProductsServices/Vehicle/Differentials/FAQforDifferentials/index.htm
Note that they do not recommend synthetic oil.
Steve
Regular gear lube 80W 90
No additive.
I see no reason why a synthetic can't be used. Nascar does. I have from time to time without any problem. Being a positive gear engagement design , the internals do not create heat in operation nor is there any possibility of slippage. Same reason friction modifier isn't needed. While on the subject. "My" experience is that synthetics are OK to use in 3.50 and "higher" ( lower numerically) gear sets . For 3.70 and "lower" (higher numerically) "I"prefer an 85-140 wt conventional gear oil , or single weight 140. Why? These gears typically have more tooth engagement ant naturally create more heat which thins out the oil more quickly. I find less gear wear with a 140 wt oil in racing applications when an oil cooler ( for the diff) isn't used and most of us don't use one. This is VERY important on Auburn and Traction loc units. True Tracs don't have clutches so they don't care.
Randy