What Fluid

[JOSH13]

I'm hoping to finish up the axle swap soon and am curious what fluids people on here are running in their diffs and what you recommend ? Any pros and cons ?

[ss346ci]

I have always used the limited slip additive from oreilly's and mobil 75-90. It never whines and I am still spinning both tires on a stock limited slip at 106,000 miles.

[RapidRick]

My GM Firebird Owners Manual lists Synthetic + Synthetic Additive. (1.75 qts. with stock 10 bolt cover).

We just changed out the original "clunking on turns" Torsen diff. with an EATON brand w/ Carbon Clutches.(not Gov-Lok GM type Eaton). My 3.73 gears were in fine shape, and I have a T/A Girdle so it holds a 'lil bit more Fluid in total.

I spoke to EATON tech support. They don't talk up synthetic at all over petroleum based due to the various multiple brands.
I told them I'm using AMSOIL and AMSOIL SlipLok Additive. Guy said " If it chatters change it out, if not you're good".
It's all in, and it's all good! Nice & quiet.

I did alot of research, and I bracket race this Bird too.
There are many opinions out there.
But after speaking to rear specialists and reading this, you may also want to go AMSOIL SEVERE DUTY 75/90 wt.
Check out the finer points and comparisons here. Test was independent, so can't blame Amsoil for making it available. Best Regards!

http://www.amsoil.com/products/gearl...hitePaper.aspx

[nicholas1752]

I have a detroit locker and they reccomend non-synthetic 80-90

[JOSH13]

I still have the stock rear , stock posi , and stock 2.73s .... Forgot to post that earlier .

[JOSH13]

The only thing they had at the shop I went to was the Redline fluid . Hopefully it will work well .