How do I know if my rear end is a posi or non-posi. The casting numbers on the rear axle housing tell me that it is a 3:08 non-posi....but when I oppened up the rear end last night I found a casting number on the gears that read 37 11 which means that it is a 3:36...which tells me that somebody rebuilt this in the past. How do I know if they converted it to a posi or not by looking at it? I don't have the wheels on so I can't spin them...is there any way to tell just by looking?...casing numbers...etc

The casting numbers on the inner gears are as follows.....GM 379062342 37 11 27

Thanks!!!!!

jack it up and block the front wheel. take it out of gear and turn the back tire forward. if they both turn forward it's posi.

Yep what he said!

A posi will have springs and clutches in the carrier. A non posi will only have the four spider gears and a shaft down the center.

Here is an Auburn posi carrier


http://www.jegs.com/images/photos/109542015.jpg

Exploded view.

http://www.jegs.com/instructions/109/diff-exploded.jpg

jack it up and block the front wheel. take it out of gear and turn the back tire forward. if they both turn forward it's posi.


thats not the fun way to test it!!!! The two vs one stripe method is far more therapeutic!

thats not the fun way to test it!!!! The two vs one stripe method is far more therapeutic!

Thats the way I test em! :D