I had posted several weeks ago about the trouble I was having with my front differential snapping the CV joint on the passenger side in 4 wheel drive. I took it to a more "experienced or seasoned" mechanic and he had the cover off the differential and felt it was not the problem. He asked why the other mechanic replaced the axle in the first place and I told him that while he was replacing the hub and wheel bearing assembly he noticed the boot was tore so he just replaced the whole axle. The "seasoned" mechanic said, "I guess I'm the only guy around here that takes the axle apart, cleans it up, regreases it and puts a new boot on it rather than throw a rebuilt axle in when just the boot is tore!" He did just that and put the old axle back in. No problems!! He's blaming bad rebuilds from NAPA since I snapped two of them and now it works fine with the old one. Just thought I'd pass it on. Thanks to those who offered advice.

I hope you returned the parts to Napa for a refund. Where I work, we use Napa parts and have no trouble getting refunds or replacement parts for defective units.