Here's an update on the situation.

I unbolted the rear diff and checked inside to make sure everything was OK and that there were no obstructions. Everything looked good as new so I bolted it back on.

I also pulled the passenger side axle to compare it with the driver side (the bad one that's been giving me the problem). My cousin and I noticed a couple of differences. The new wheel bearings on the driver side were not as flush, or deep-seated, into the backing plate as the new ones on the passenger side. I also noticed the driver side bearings had about 1/4" play when wacking on top of the splined axle end. I don't know if this play is normal or bad, but just in case I'm taking both axles to the dealer to check them.

The other difference between the axles is that the passenger side has a nice, smooth tapered splined end. The driver side does not. I believe this may be the reason why the driver side axle only goes in the axle housing area just a tad. I've been using the passenger side as a guide to go by as I try to file down and taper the splined axle end on the driver side. Once I get the axles back from the dealer, I hope I was able to taper the end down enough so that it'll slide in easily.

I'll keep y'all updated on the situation and hope my experience so far can help anyone else who may have a rear axle re-install issue (although I sure hope no one else does have this problem because it sure is frustrating when a 1 to 2 hour "easy" job turns into having my truck sit on jackstands for days at a time!).

Take care,