Originally Posted By: Clevy
Shockproof heavy in my tranny,20000 mile intervals. Rotella t 15w-40 in the primary and engine,3000 miles,both drained at the same time.
This. I do my primary every other oil change. Brad Penn 20-50 in the motor,Mobil 1 75-90 in the trans,Valvoline 20-50 MC oil in the primary.