Hey Guys,

Quick question.... who is running "what" for rear end fluid?
I have a Nostalgia Super Stocker... 3200LBS... ford 9 inch....
Doing a fluid change...looks like 90/10 to me.. I know some guys are running synthetic fluid but Im not so sure I like it for rear gears! Seems to me that the gears would be better protected by a petroleum based product due to the heavy loads and shock factors... what do you guys think?

Thanks..

I use Redline Heavy ShockProof it has low viscosity until it is shocked then it goes to 75w250. I don't think I would get the 75-80 passes out of my street gears before they start to crack with regular gear oil.

Click here for Redline product info page

This is what 75 runs on street gears looked like with transbrake 6000 stall and a heavy car...

street i run 90-140, racin run 50 w oil

I run all synthetic fluids

75-140W Synthetic. 4 years now and the gears look like new. Footbreak car, 10.00 @ 135 mph typical ET, 3500 lbs w/driver.

Scheifers 250 WT, you must warm it up before each run when cool or cold outside All the new cars come with synthetics evrywhere they can run them, my 2006 Ram 3500 4wh.dr. calls for synthetic in both rear ends and the transfer case, I use the Redline brand synthetics gear oil in it

Redline Shockproof here too.

Been using Valvoline 75-90 syn. for years in my 8 3/4.........maybe that`s why it`s still alive..........

I've been using Amsoil Severe Gear 75w-90 in my differentials for years. My gear guy like it as well because it provides longer life for the gears as well as bearings!

Amsoil Severe Gear 75w-90

They also have a 75w-110 and 75w-140