Any tips on buying a used posi rear end?

[Cutlass3800]

I might be buying a used 8.5" posi rear end, but I have no clue what to watch out for. Does anyone have some advice, photo's, or links to articles that could help prepare me so that I don't buy a piece of garbage?

TIA

 

[Cutlass3800]

For the benefit of future generations utilizing the search functions of this fine board.....

I received one PM advising me to walk if there are any metal bits in the fluid and to check the pattern. Unfortunately I don't know the details on how to check or even what to look for in the pattern and I couldn't find a lot on the Internet regarding the subject so I've decided to pass on the purchase for the time being. My plan now is to ask Santa for the $30 "Rebuilding Your Differential" DVD by Paul Zank so I can learn more before shopping for a differential.

 

[cleetus]

You'd need to pull the cover off the rear and look inside. You would notice if the pattern on the teeth was strange.

Make sure it's a posi by spinning one wheel and making sure the other spins IN THE SAME DIRECTION. If it goes backwards, it's an open rear.

Wiggle/turn the front pinion and make sure there isn't noticeable play or wobble in it.

Look for cracks near the carrier/axle tube. Check for leaks near the backing plates.

If the guy is trustworthy and knows his sh*t, that's the most important part of the sale.

Doing all that stuff (aside from removing the cover) takes about 2 minutes.

 

[monzaz]

Just to add:

-Make sure with any rear- DO turn the rear end ring gear at least one full revolution as to check fro rust from sitting out of the fluid too long.

-Any rust on the teeth could be a iffy deal. The ring gear teeth should be smooth and shining clean bare metal across both faces of the gear coast (convex side) and drive side (concave side) of the gear face. NO triangulation pattern of discolored bluing or brown spot should be present.

-The spinning test is iffy sometimes if someone has done a Lincoln locker on it... This is why opening is almost a must. (it will also depend on HOW much you are spending too on the deal.

-Ask you questions before you check the rear as to see how honest this person is and how much matches the horses mouth...LOL. [-X

-Leaks are also a good way to determine maintenance : if the thing has leaks out of it everywhere it may have been neglected in its life.



So hope this helps again