posi or non-posi
Thread Starter
Instructor
Joined: May 2004
Posts: 127
Likes: 0
From: Aurora CO
posi or non-posi
We have a 69' that we have recently purchased. We thought the car was a non-posi rear end. This is due to the fact with one wheel off the ground you can spin the wheel. We just found the id # on the case which are: 2AM910/69w. when we looked this up it appears to be a 3.36 posi rear end. Can anyone verify that this is a posi rear end? And if so why is it acting like a non-posi rear end?
Thread Starter
Instructor
Joined: May 2004
Posts: 127
Likes: 0
From: Aurora CO
Re: posi or non-posi (wombvette)
Ok second question. If the clutches are worn out how high on the priority list does rebuilding the differentisl need to be? Will it hurt to drive it until fall then take it all apart this winter or should it be sothing I do right away to prevent further damage?
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: posi or non-posi (MPSJM)
With both wheels off the ground, if you spin one wheel, the other rotates the opposite direction you have a non-posi. If the opposite wheel rotates the same as the one you are spinning, you have a posi.
Instructor
Joined: Apr 2004
Posts: 106
Likes: 0
From: Norfolk VA
Re: posi or non-posi (MPSJM)
MPSJM,
If your unit is a posi, before you spend money to rebuild it, try changing the gear oil using GM Posi Lube. This simple fluid change can sometimes fix a "worn out" posi.
Hope this helps
Todd
If your unit is a posi, before you spend money to rebuild it, try changing the gear oil using GM Posi Lube. This simple fluid change can sometimes fix a "worn out" posi.
Hope this helps
Todd
Race Director
Joined: Feb 1999
Posts: 19,659
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From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
Re: posi or non-posi (lps&vettes)
According to the information I have, all 69 ratios were posi except for codes AK 3.36 and AS 3.70. Compare this to the code stamped on your rear diff and if these are one of the codes, you have an open diff. Otherwise, you should have a posi. 
