Originally Posted by 88n94

If it was my truck I wouldn't replace the bearing unless I thought I had reason to.

Originally Posted by 95fiveoh

I wouldn't worry about those grooves. It appears pretty normal. I wouldn't bother replacing the bearing unless you know it's making noise or you have a drive line vibration from it.

Originally Posted by midwestbird

I've finished with the seal replacement. Now that I've had it apart and back together, I see now that -- just as you stated -- that wide groove I was concerned about was not from a bearing. I ended up reusing the yoke ( a new one is $100+).. The pinion nut was very difficult to remove and reinstall -- I'm not sure if it is supposed to be that hard, but I couldn't get the nut back on with a 90 psi impact wrench; I had to use a 3x torque multiplier to get it retightened. As we got near the old nut position, it clearly become nearly impossible to move the nut, which is where we left it. At this point, if the seal doesn't hold, I'll just take it to a transmission shop in town. Thanks again.

Originally Posted by 88n94

That nut should turn somewhat hard, so it stays where you put it and doesn't turn loose, but not necessarily that hard. As long as you got it tightened the correct amount is all that matters. It should be tightened JUST enough to take all up and down sideways play out of the yoke.