View Single Post
Old 11-10-2019
2007-52 2007-52 is offline
Senior Saleen Forums Participant
Join Date: Aug 2014
Location: Longmont, CO
Posts: 139

I believe Saleen's "Max Grip" differential was a "Detroit / Eaton TrueTrac"... which is the same as a Torsen. The Max Grip diff was an option for any Saleen car. This style of diff uses helical worm gears instead of clutch packs and spider gears. You can't tell what your car has from the outside. You'd have to have the window sticker, or you could contact Saleen to see how your car was built. I thought many (if not all) of the PJ's had the "Max Grip" diff?

The Torsen-style diffs do NOT use / need any friction modifier. Only differentials with clutch packs (limited slip or "traction-lock" diffs) need friction modifier.

Most differential fluids have friction modifier already added. Redline offers 75W-140 both with, and without, friction modifier. You want to use 75W-140 in your differential... NOT 75W-90. Even your Ford owners manual for the Mustang will recommend 75W-140.

You only need to add friction modifier if you are putting straight lubricant in the differential and the differential is a limited slip style. When you buy Motorcraft 75W-140 it is just straight lubricant, and thus, you need to buy the little bottle of friction modifier too. If you go to your local auto parts store, virtually everything on the shelf will have friction modifier already added.

"Need" to add friction modifier is a little subjective too. It won't hurt anything not to add it. You would only possibly get some chatter in hard turning because the clutch packs wouldn't slip against each other as easily... In other words... It would act more like a posi diff without friction modifier... But most people couldn't tell, or notice, any difference.

Your 3-valve engine was designed to work with 5W oil. It uses variable cam timing which involves solenoids that actuate valving to flow more and less oil into the timing chain gears, which advances and retards the cam shafts. Also, the timing chain tensioners work on oil pressure. Basically the engine is very oil pressure dependent. You should note that even for the GT500 Ford recommends 5W-50 (still a 5W oil)

Saleen and Ford recommended 5W-30 in your engine. For supercharged 302's Saleen recommended 10W-40.

Sent from my SM-N975U using Tapatalk
Reply With Quote