Hi, When the tires are spun in a non-posi (open) differential, the pinion or spider gears spin on the pinion shaft. Enough tire spin and it will wear the pinion shaft excessively. This sounds like your problem. As you start to push the shaft out the pinion gears are catching in the worn area. A little jiggling, rotating and pushing should do the trick. If worn severe enough it might take a little coaxing with a hammer and a brass drift. I have seen a couple of diffs where the shaft is worn completely into, needless to say not a lot left. John
