posi differential passenger side wheel locked - won't turn

[Ian G.]

Hi all,

I had my posi differential rebuilt professionally many years ago and just got the rear-end put together for the first time, put on tires etc for a rolling chassis, but it doesn't seem right. I cannot push the frame at all. If I jack up the rear-end, with both wheels suspended off the ground, I can turn the driver's side tire and I can see the yoke spinning. However the passenger side tire will not turn at all. Inside the rear-end guts is a new eaton posi in an original 3743833 P case. I thought they should both turn in one direction with a posi and in opposite directions with a standard differential... Looking in the service manual it seems perhaps the pinion and ring gear is too tight, but I can't see anything in there about the wheel simply not turning. Right now there is no engine installed or driveshaft, just the rolling chassis.

Any help appreciated...

[Donald H.]

Re: posi differential passenger side wheel locked - won't turn

Probably a dumb suggestion, but is it possibly the passenger side brake is locked?

I had the same set up. Original P case and a modern Eaton. I used Tom Parson's very
good written rebuild instructions when I did the rebuild. Mine was a 60.

[Ian G.]

Re: posi differential passenger side wheel locked - won't turn

Not dumb at all. Very possible. That's what I'm looking at now.

The brake shoes shouldn't be locking, they were loose with the drum going on, but the drum itself seems to be wedged over the axle center. I think the hole is too small. It's these horrible Chinese (or whatever) reproduction drums with the springs. I had to have 0.2 machined off one so the front drum would turn. it was .2 under 11. I noticed the hole was very tight going on over the rear axle. I remember before I put the drums on torqued, the wheel would turn now that I think about it. Just cracked the darned thing trying to get it off wth a hammer (the rubber mallet didn't budge it, nor a drift). I wonder if American made ones would have done that? If I can get it off without ruining my brake plate I will get American drums and to heck with the points.

Not my day or year with this corvette.