Recently had the same problem on mine rear LH drive flange came loose. HD flanges have been on for 6 years but ARB Lockers fitted 10-12000k ago. Loosened off after a bit of rougher offroad (using the locker) and then a freeway run.
Anyway bearings were a little loose (nothing severe) so tightened, cleaned and a little loctite - will see how they go from here on.
Had done some long and severe corrugations since the flanges were last off.


Martyn