1986 K30 ex army truck with 14 bolt detroit locker. Im checking brakes, wheel cyls, repacking front brgs, and changing all fluids tomorrow. What gear lube should I use in that rear? Does it need any special additive?
Is ATF in the NP208 transfercase OK?
Thanks Pete

ATF in the transfercase is fine. You can use 90 wt in the rear. I usually use 75-140 synthetic in mine. You shouldn't need an additive if it is a Detroit locker.