Not quite. The bearing race must be fully seated. You adjust preload using the appropriate shims between the retaining flange and housing (other end of the differential) upon assembly. This is quite critical, so be sure to follow the directions in the factory service manual.I think I may have worked this one out myself. Once I tighten the carrier cover to the correct torque it should seat the race so it is on zero preload.
I know you've already removed the bearing races, but I'll throw out another possible method for it. I haven't tried it on the X case yet (I'll be rebuilding three of them eventually), but this has worked for me on very similar races in other trans. Using two small "claw foot" pry bars, you can 'walk' out the races. The bars I'm referring to look like this:
View attachment 32630
The tip (red arrow) gets behind the race in the recess. Then they can lever the race up from side to side.
If the race isn't stuck you may get it with only one bar. But don't over do it in one spot or you could damage the case.
I think I may have worked this one out myself. Once I tighten the carrier cover to the correct torque it should seat the race so it is on zero preload.
Although this method has worked for me many times with other similar trans, I can see why it wouldn't be a good idea for these old Fiat units. When I look at the images of case failures (such as in the thread linked below), it makes me think these aluminum castings are much more brittle than the ones I'm more familiar with (other makes of vehicles from the same era). There are times when a bearing race lives in a blind hole and no access from the other side. I have one of the pullers designed for such applications but at times it doesn't get the job done. And that's when I use the lever method. Luckily I've never had any damage from doing it, but as I say that's with other makes of 70's FWD trans. So I'll definitely avoid it with my X trans.Don't use that to try and pull the diff bearing race. You'll crack the case too easily.
Steve and Peter, would it help to try and polish out the rusty surfaces? I realize that would be a bit time consuming for the gear teeth. But if it will help the current shaft to live longer and run quieter, then that gives greater opportunity to find a suitable replacement. Or are there any surface finishing techniques that will work here...blasting, tumbling, dipping, coatings?I'll reassemble and use this until I can source a replacement input shaft.