Just making sure of a few things before I go get greasy and dirty...

1990 started the years of "all" 28 spline axleshafts, right? 1989 was the questionable year?

I have an '84 Eaton gov-lock in my 3.73/busted posi/disc axle, from an '84 trans am. I assume that it's a 3-series carrier from the factory? I'd hate to buy the SLP posi and find out my GM gears don't fit. Yep, they are GM gears (inspected them before I bought the axle).

And last question, a snapped lock bolt can be worked out with picks? I'd hate to snap the bolt in the junkyard, but if I do, I want to be prepared- I'll buy a set of picks before I go. Is it true that the only thing that really keeps a bolt "tight" is the clamping of the bolt head against the surface? So without a bolt head, the snapped lock bolt should spin easily?

Thanks in advance for a quick answer! I'd love to get this 3.73/posi/disc axle back under my car. Future tip for 84 owners with Eaton gov-lock's: If you put the recall kit on your rear calipers, don't get overexited and start driving around for a couple weeks, enjoying your "finally working" rear brakes. Make sure to readjust the emergency brake levers so they don't drag- which confuses the gov-lock around turns- which winds up with a busted center.

 

from what i can tell by looking at the old carrier from my car, yes the only thing that really holds that bolt in is the pressure from the head, you will have to contend with some friction from the crosspin, but it should come out fairly easily


was that eaton gov lock a factory item? could it also have come in blazers?,

my friend had one that you could jack up and spin a wheel it would act like a regular open rearend, then after about 2 revolutions or so it would lock and be a posi,

 

It might've. In '84, something happened with Auburn; either their supply was low, or they had a fight with GM- I can't remember. So they went with Eaton gov-locks for '84. It's an actual locker, not a posi, but the design is such that when the governor flies open, it can damage the spider gears by knocking pieces off- that's how mine finally destroyed.

Thanks for the info on the lock bolt! Man, I hope the thing doesn't snap.

 

I've always gotten the broken off bolt out with a dental pick. There's no torque on the threads and usually only about 1/2 a thread is left on the bolt when they break.