Gear Lube?

[suzuki-guy]

what kind of gear lube should i use in an auburn 10 bolt 8.5 positrac limited slip unit? i want to use the best and dont care about the cost. can i use synthetic? is the gm positrack additive ok to use in these units? thanks CODY

[dlstewart01]

You need to ask Auburn as some aftermarket manufacturers do not recommend synthetics. And it being a true limited slip you will probably need an additive.

[Ryan00TJ]

I'm pretty sure Auburn did not recommend using a Synthetic in their units in the 98-02 Fbody's. Just regular 75W-90 with the slip additive. It's due to the clutches in the unit and friction. Check with them to make sure.

[wreedZ71]

Does my 97 Sururban have a auburn rear end? I was about to change it with full Syn Amsoil.

[Z45]

Not likely. GM does not use limited slip differential in pickup trucks unless its a 4-wheel steer vehicle. No Auburn rear differentials are installed in trucks and SUV's, the axle is made by AAM and the locker is made by Eaton.

 

 

 

 

Testing has shown that the new synthetic lubricant will chemically attack the Room Temperature Vulcanizing (RTV) sealant. Use only the non-synthetic lubricant, P/N 1052271, in axles using RTV sealant (See 9.5 and 10.5 information below).

 

American Axle and Manufacturing (A.A.M.) has approved the use of the new Fuel Efficient SAE 75W-90 synthetic axle lubricant for rear axles with the following restrictions:

 

All 8.6 inch axles are compatible as originally built.

9.5 inch axles on vehicles built prior to mid-February 1998 are NOT compatible because RTV sealant is used on the cover pans. On vehicles built after mid-February 1998 and equipped with 9.5 inch rear axles, synthetic lubricant, P/N 12378261, can be used because the RTV was replaced with a gasket. Other mid-February changes to the 9.5 inch rear axles include a new cover pan and cover pan fasteners common to other axles.

 

Important

The new cover pan is not retro-fittable to the housing of 9.5 inch axles on vehicles built prior to mid-February 1998. A new retrofit kit is available that will enable the use of synthetic lubricant for vehicles built after mid-February, 1998.

 

 

All 10.5 inch axles prior to March 3, 1999 are compatible if the axle shaft hub seal (RTV) is replaced with P/N 327739 gasket when changing to synthetic lubricant.

As a product improvement, this new lubricant has been released into 1999 current production C/K vehicles built after the above VIN breakpoints (Except HD3500 models which use 75W-140 synthetic lubricant, P/N 12346140).

 

It is recommended that synthetic lubricant be used when changing rear axle lubricant for the following reasons:

 

Potential fuel economy

Lower operating temperature under severe usage conditions

 

Important

You do not need to wash/rinse any non-synthetic lubricant from the axle cavity when changing over to a synthetic lubricant. However, you should remove debris from the magnet and the bottom of the axle cavity whenever the axle fluid is changed.

On light-duty trucks equipped with locking differentials, do NOT use a limited-slip additive.

[VR021302]

The Auburn put in my old truck said DO NOT USE SYNTHETIC FLUID, it will void the warranty. But the GM limited slip should be fine. Mine recommended that I use factory limited slip additive.

[suzuki-guy]

the diff i have in my truck now came out of a stock 1997 z71 and it is an auburn

[MS3DALE]

the diff i have in my truck now came out of a stock 1997 z71 and it is an auburn

 

If the diff came out of a "stock" '97 Z71 it is not an Auburn,As mentioned before GM didn't use Auburn's in the trucks,they used Eaton lockers. Someone may have added an Auburn,but it wasn't stock.