Rear end question

[ron19]

My 65' came with a 12 bolt rear. I want to add posi traction to it. Anyone done this, or know what would be the best way to go on the street?

[LILRED66]

I have purchase posi-units and master set-up kits on eBay or you can post an ad in the Parts Wanted Forum for a factory 12 bolt posi unit or check your local pick-n-pull for a used one.

[fchava]

I put a tru-track in my 12 bolt.

[merlin65]

I looked on craigslist until I found a guy selling a 373 posi unit out of his truck for 100 bucks. Looked inside and it looked great. No problems to date. I would say look around and save some money.

[TR65]

I put a new Eaton posi in my 65 12 bolt a few months ago (from Jegs, or Summit). I kept the same gears so the pinion position stayed the same. The lash on the ring had to be reset since the posi carrier is not the exact same dimension. The only hassel I had was getting shims the correct thickness. I finally had to machine some.

I used a cast aluminum rear end cover for looks and increased oil capacity. That was fine until I tried to hook up the panhard rod and it hit the new cover which sticks out further. So then I fabricated a new offset rod....

Pretty much one aw shucks after another. But it works and looks fine now.

Good luck.



TR

[ron19]

Originally Posted by TR65

I put a new Eaton posi in my 65 12 bolt a few months ago (from Jegs, or Summit). I kept the same gears so the pinion position stayed the same. The lash on the ring had to be reset since the posi carrier is not the exact same dimension. The only hassel I had was getting shims the correct thickness. I finally had to machine some.

I used a cast aluminum rear end cover for looks and increased oil capacity. That was fine until I tried to hook up the panhard rod and it hit the new cover which sticks out further. So then I fabricated a new offset rod....

Pretty much one aw shucks after another. But it works and looks fine now.

Good luck.



TR

TR, how do you like how the Eaton hooks up? How well does it take corners? What gear ratio are you running in the rear?

Thanks.

Also, Merlin, good suggestion on the Craigs list, I'll check it out....

[greg64]

I've also got the Eaton limited-slip in my 77 C10. I'm running 3.42 gears on it. My original carrier was shot, and I was thinking about going to a posi, so I killed two birds with one stone. I've been driving it for 6 months now and I really like it. In a straight line, there's no doubt that both tires are pushing. It's helped me in the snow as well. The only trick is cornering on wet roads. If you give it too much gas, BOTH back tires will break free, which can lead to some interesting slides.

The posi doesn't limit cornering, but you can feel it protesting when turning as tight as possible. I pull a trailer, so I find the extra traction comforting.

[TR65]

Ron19,

Hooking up is not exactly an issue with the stock 283 in my truck. (I am getting ready for a 6 litre LS2 and T56 that is sitting in my shop.) But the Eaton works good, no grabbing etc, good traction on slick surfaces. In fact it works better than my 08 Vette posi which grabs at very low speed tight turns.

I was considering the Auburn Gear posi but some racers said that the Eaton was more reliable and lasted longer.

Don't forget to add the friction modifier to the oil.

TR