HELP Please- 12 Bolt Eaton Differential 1966 Posi Traction Unit

**Judges4u** · #1 09-28-2017, 08:45 PM

Been a while since I posted here; good to be back.

Now I have buddy who has a 68 Camaro with the 12 Bolt Eaton Differential 1966 Posi Traction Unit (added from stock). We're swapping out the drums for discs.

Anyone know the procedure for removing the C clips? Haven't worked on a posi unit before. There is a spring cage in the middle that blocks the C clip removal. I assume remove the spring cage to have access to the C clips See pics? Oh, when I pulled the pin out, one of the spider gear bronze washers slid out! Ugh, I'm thinking the only way to assemble correctly now is removing the entire unit. If I have to remove the entire unit (remove bearing caps, etc.) can I re-install and not have to worry about using a dial indicator since the ring gear was removed.

Thanks in advance for any advice / help. Youtube doesn't have any videos for step by step process of an older Eaton Posi like this. Semper Fi. Goat

**ssl78** · #2 09-28-2017, 09:40 PM

You shouldnt have to remove anything, if you push the axle all the way in once the pin is removed just enough but not all the way you should be able to get the c clip out. You also should be able to get the shim back in by rotating the diff pin in enough to get the shim back in. But you never want to take the pin out all the way out but if you do dont rotate the diff.

**earntaz** · #3 09-28-2017, 10:34 PM

A trick I learned many eons ago was to insert a 1" piece of hard foam rubber into the cross shaft hole on each side when removing the cross shaft. That will hold the gears and spacers in place. TAZ

**Judges4u** · #4 09-29-2017, 12:12 AM

Thanks for the input. Hard lesson learned.

I took more pics, you can see the clip will not fall out. Pushed the axles in and tried to remove with a magnet. I guess what I need to do at this stage is get the pin back in after I get the bronze shim back in place behind the spider gear.

**Judges4u** · #5 09-29-2017, 12:13 AM

Thanks Taz. Next time, I'll check the forum first. I've never had experience with a posi unit. The open DIFF, is so simple.

**Judges4u** · #6 09-29-2017, 12:14 AM

Question. Once I get the pin back in, you say I should be able to remove the clips? Thanks

**earntaz** · #7 09-29-2017, 01:40 AM

No -- once you get the pin out and secure the side gears, push the axles in (with brake drums removed) and the C-clip can be removed. To re assemble, push axles all the way in, slide C-clip onto end of axle and push axle back out. With C-clips installed and both axles pushed out, the shaft can be reinstalled -- you may have to wiggle the gears some to get the shaft aligned. TAZ

**big gear head** · #8 09-29-2017, 02:02 AM

Do not remove the springs. If you do you are in for a lot of work trying to get them back in.

I recommend replacing the bronze washers with new steel washers. You can install them without removing the differential. The easiest way to get them back in is to go in through the small hole on the opposite side of the differential. The preload springs and plates are not in the way on the back side. It's not easy to get them in, but it certainly can be done. It's been done hundreds of times.

**Judges4u** · #9 09-29-2017, 06:25 AM

Gents,

Problem solved.

I rotated the pumpkin and was able to work the brass washer back in, and then I took two PVC pipe tubes and inserted where the pin slides through to keep the spider gears and washers from moving again. When that was done, the axles went in farther and I was able to remove the C clips. Thanks again for the help Brothers. S/F Goat

**earntaz** · #10 09-29-2017, 11:07 AM

Glad to help -- that is what this "insanity" is all about ... TAZ