So I am putting together a new 9? rear for the racecar?4.56 pro gears, spool etc. I have always run Royal Purple Synthetic gear lube but now my contact at Mark Williams is telling me to avoid synthetic and go with a mineral based 85-140 with a GL-6 rating. He is saying some of the gear manufactures are going away from recommending synthetics because it is not coating the gears properly. I was hoping to get the car out on Friday and the local speed shop stocks Royal Purple and Valvoline in the 85-140 but they are rated GL-5? What are you guys using in your rear, mineral based or synthetic lubes?
Did I really just ask that question!?!?!?
[:-bigeyes2-:]
Wanna see some pictures?
http://public.fotki.com/JoeGrippo/