[jvoiles]

I'm rebuiding a 12 bolt that I picked up. It's out of a 66 chevelle with a series 3 carrier. I do not know how well it operated in the previous vehicle(it had been adapted to a different 4 link system). I need 3.73 gears, an install kit with all bearings and some advice. I took it apart myself and took notes on which shims went where etc. etc. I have two questions, the axles have a little pitting where the bearings are near the flanges, is this OK? Is it complicated taking the carrier apart to inspect it and what are the signs of needing repair/replace.

 

[big gear head]

Send me am email and I'll go over all of the parts for you. biggearheadbellsouth,net.

 

[tlowe]

That housing is going to use the thin steel shims. Those do not come in ANY kit out there. I have a big stock of those shims.
Is there a posi in it? If not this is a good time to add one. I can supply you parts. Tom [email protected]

 

[Lionel-n-Chevelles]

Disassembling the unit and inspecting the individual components is critical to reading the actual condition of the Posi Unit. You have to have the clutches out where you can view that actual wear surface. Dark gray to black is good as long as there are still visible grooves in the surface. If there is a shiny tint towards the center of the clutches with a dark outer ring, then there is about 50% life left. If the clutches are shiny across the entire surface, then they are shot.

You can rebuild your Eaton 3 Series Posi with Eaton Part Number 29403-00S which are 18 steel discs, guides, and shims. This is what the factory used. Also install a new Eaton 400 pound Spring Pack, Eaton Part Number 29590-00S

 

[461RAT]

Correct me if I am wrong,but I believe the correct part number for the clutch kit is 29426-00S.The other part number(29403-00S) might work but I think its more aimed at the 8.2 and 8.5 setup and the other part number I mentioned is more universal.I could be wrong but its worth mentioning.The 400lb spring pack part number is dead on correct.

 

[Lionel-n-Chevelles]

I build a lot of 12 Bolts and the Eaton Part Number is correct for the 8.2 Eaton 10 Bolt Posi and the 8.875 Eaton 12 Bolt Posi. The 8.5 Clutches have a squared tab on the eared clutch plates. The 8.2 and 8.875 have a rounded tab on the eared clutch plates. The 8.5 and 8.875 Clutch Plates are not interchangeable.

http://www.chevelles.com/forums/showthread.php?t=306014

 

[big gear head]

The 8.5 clutches are no longer available. I'm hopeing that someone reproduces them soon.

 

[461RAT]

I build a lot of 12 Bolts and the Eaton Part Number is correct for the 8.2 Eaton 10 Bolt Posi and the 8.875 Eaton 12 Bolt Posi. The 8.5 Clutches have a squared tab on the eared clutch plates. The 8.2 and 8.875 have a rounded tab on the eared clutch plates. The 8.5 and 8.875 Clutch Plates are not interchangeable.

http://www.chevelles.com/forums/showthread.php?t=306014

Thanx for the additional info.I was just curious because Im in the process of rebuilding a series 3 posi right now and we ordered the part number that I mentioned for the clutch pack.I wander why theres 2 different part numbers but they still produce the same results at the end of the rebuild.

 

[Tom Mobley]

Jon,

Before spending money on the 3.73 gears you need to verify you have a 3-series carrier.

 

[Jim_66SS]

Seems that Summit and Jegs list the 29426-00S for the 12 bolt.

http://www.summitracing.com/parts/ETN-29426-00S/?rtype=10

These seem to have the round tab; but somtimes photo's are wrong.