I posted a question about this several months back. The rear end is a 14bff with Detroit. When you let off the gas, or "tap" the gas the drivetrain makes a loud clanking/banging noise. It sounded like it was coming from between the transfer case and trans. Some here suggested it might be a drive sleeve, which sounded reasonable to me. Today, a mechanic who really knows his stuff drove it and looked at it, and said that it was the locker, or something about the locker. We jacked up the back and played with it. While driving down the street, the locker acts like it's taking a corner and only one side really gets the power. When only one side is engaged, there is much more "slop" in the drive. However, when you get them to both engage while jacked up, the slop all but disappears. So he thought that maybe it's not driving down the road quite straight or that one side of the axle may be a little out front of the other (I have blocks in the back for now). This would make the locker "think" that it's taking a corner since one tire would be spinning faster than the other. This usually happens when tires are different sizes, but these are identical. Anyway, thought I'd post in case anyone else runs into this.