Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
You took the yoke off to replace the pinion seal, is that what's going on?
When you tighten the pinion nut, that should tighten up the yoke and take the play out, yes?
What are you tightening the nut with? An air tool or just by hand?
Sometimes the outer pinion bearing gets a little weird and wants to try to go on a little cockeyed. That's the only thing that comes to mind on this, is that the bearing isn't sitting right for some reason. But, it shouldn't have come off the shaft of the pinion.
You just put the seal in, no other parts?
That shouldn't make any difference at all. You didn't disassemble the differential or anything like that, right? There's not a need to even take the cover off the differential or lose any substantial amount of fluid.
Typically, the nut comes off, the yoke comes off, the seal comes off. New seal, reinstall yoke, tighten to previously made marks, or at worst, go slow on it with the impact until the yoke bottoms out (the air tool will simply stop moving the nut at the point where the yoke, bearing, and crush sleeve are all against each other).
Did you remember to put the washer under the nut?