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338 Posts
Discussion Starter · #1 ·
Obtained a used Auburn posi and dissasemled it to see if it was suitable to install in my 96RMW.
I have never taken one of these apart so I would appreciate comments from anyone who can tell me if this is a good casing and cone assembly .


8,570 Posts
Thanks for posting - never saw one. I hear they're either impossible, or, just real difficult and not worth the effort to rebuild. Everybody seems to prefer Eatons or simple gear lockers.

Premium Member
6,396 Posts
There are no internal criteria, per se. The Auburn's performance is a matter of conducting a test (see the FSM) to determine whether it's within tolerance.

I contacted Auburn in 2008 with some specific questions--here's a synopsis of the reply: (should have shared this long ago)

----- Original Message -----
From: "James Forrest"
To: <[email protected]>
Sent: Thursday, April 24, 2008 8:34 AM
Subject: Re: 94 Impala SS with Auburn LSD

Please find the answers to your questions below.

1. what is an acceptable axle float/end-play dimension, as far as internal to the differential and LSD function?

Axle shaft end play is dependant on a multitude of components and their respective tolerances. This can range from .001" to .039" but is typically in the .020" range. The .023" and .026" readings observed are in the ball park. An Auburn unit with a lot of wear will result in additional axle shaft end play which can exceed .060".

2. is there a specific Auburn test procedure for testing LSD function that may be different in any way from the OE prescribed procedure?

We prefer the following procedure for checking the LSD function:
1. Block the front and rear of both front wheels
2. Raise one rear wheel off the ground (does not matter which)
3. Place transmission in neutral
4. Using a torque wrench on a lug nut of the raised wheel, measure the torque required to rotate the wheel.
For the 8.5" unit in the Impala SS, 60 lb ft is a good result.

As far as noise goes, we recommend non synthetic 80W90 oil treated with GM limited-slip additive at 3 oz. per quart of oil.

I hope this helps.

Best regards,

Jamie Forrest
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