Third Generation F-Body Message Boards - What should I use for rear axle and differential lube?

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What should I use for rear axle and differential lube?

I've got a 9 bolt 2.77 posi, just curious as to what kind of lube to use when I refurbish the rear. I've also heard that posi additve is not needed when using synthetic lubes. True? I will likely go with synthetic. Any help or suggestions would be appreciated. Thanks guys and gals.

R.I.P. Blaise Alexander.

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Ed Miller
Charlotte, NC
1991 RS, 305 TBI,
bone stock driver;
1988 IROC L98
TPIS Fast Pack, modified MAF, MSD 6A, Dynomax cat-back so far.

"Do you want to race or don't ya? I want to race." Dale Earnhardt

i use the gm posi additive reguardless of what the oil makers say. i'd use amsoil synthetic if it were me. if you can't find amsoil in your area look up five7kid here, he's a dealer for it.

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

Quote:

<font face="Verdana, Arial" size="2">Originally posted by ebmiller88:
I've also heard that posi additve is not needed when using synthetic lubes. True?
</font>

Not completely. In the past, the recommendation was to see if you needed it after switching over - if so, add it (at least with AMSOIL, most of the time it wasn't needed).

The AMSOIL Series 2000 gear lubes, however do not need the additional friction modifier from the tube. It's already in there.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. 2-1/2" cat-back, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 CC system w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker 2055 headers, 3" Catco cat & 3" catback, restalled TC, Spohn SFCs).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).