Went to a dealer that had 3 07 OR's on the lot and 1 used 06 OR. Checked the diff covers. Mine, a 05 OR and the 06 OR on the lot had no inprinted numbers or letters on the covers. All 3 07's had numbers with 36-06 large and easy to see. So... I would conclude that the new and OK diffs are easy to spot.

And...talked to the service manager, said only one X has come in with diff problems, numerous Titans have been in with problems, interesting. (Mossy-Oceanside)