Eworx, well when I first got my XXX-T, I put mine in backwards.. Before the first pack was dead, the diff was barking. I assumed it was just breaking in, so I retightened it and ran another pack.. Same thing.. Man, this thing takes a long time to break in, right? Retightened it.. I must have retightened the thing 10 times before I finally gave up and flipped it over. It worked fine once I did that. You must have some SPECIAL diff that works either way, cuz the rest of us got one that needs to be on the left..