JEB99TA

iTrader: (32)

DO NOT PUT SYNTHETIC in your Strange 12-bolt if you have the Eaton HD posi unit option!!!!! It will cause your rearend to sound like it's coming apart.

Believe me, I have had my rearend COMPLETELY disassembled twice ... finding out the noise is caused by synthetic fluid. Eaton warns you against using synthetic fluid with the kevlar clutched HD posi. DAMN! I wish I had remembered that when I had my Eaton HD unit in my old 10-bolt!!! Anybody else learned this hard lesson? Hope this helps if anyone is having different noises coming from their pumpkin with a HD Eaton posi.

staringback05

iTrader: (8)

thanks for being the hamster

MeentSS02

iTrader: (11)

I had actually heard this before, but it always helps to have someone else share their experience

JEB99TA

iTrader: (32)

No dude ... you got it ALL wrong ... the gerbil man ... the gerbil ... lol!

BlackScreaminMachine

iTrader: (17)

I always use Dino oil with the car manufacture additive. Never an issue. I once had a diff serv and the tech (my brother no less) didnt put it in and I had a horrible noise on tight turns. Once added it went away.

JEB99TA

iTrader: (32)

Dude ... mine's a noise like unlubricated polyurathane bushings squeaking when slightly turning right or left at slow speeds ... and a little gear clattering when turning slightly, as well. No noise when I turn hard or on straightline accelerations or decelerations ... and there's a whistling like a jetliner coming in for a landing. It's definitely coming from the center section.

MeentSS02

iTrader: (11)

Even with the regular oil (it still makes noise)?

BlueB4C

iTrader: (9)

Yeah, mine howls like a bastard too, I put royal purple in it....was this a mistake? What is everyone running for dino oil to make it quiet(er)?

chicane

A straight weight 140.... and not a multi-vis either.

My personal recommendation would be for a Schaffer #209, straight weight 140 with the suspended moly... and 4oz of Ford Motorsport friction modifier, if you can still get the older stuff. I believe the part number is: M-19546-A

MeentSS02

iTrader: (11)

I had an easier time sourcing Torco gear oil...I'm currently using their 85w140 RGO (non-synthetic). I also use their GM friction modifier, although they offer the Ford modifier too (might try that in the future with a gear oil change).

fortmyerspolice

iTrader: (7)

i wish you could use dynamat on rear ends

Proud2bSS

iTrader: (2)

For my Eaton posi (2002 install), Eaton recommends oil weight SAE 80W90 (API-GL5 Level). I use Pennzoil. Also add GM limited slip additive part # 1052358 (or equivalent).