I've read in JP that the lock itself is a hard working item. It is pushed by air pressure into the side gears locking them together- they can't spin independently. When they can't spin, the diff is locked. Once you have the locker on the bench, you can spot any rounded off or gouged items and maybe replace them. I just had my d44 locker out and in. In the process, the two air seals took a beating. Quadratec is delivering two new seals this week. They sell all the parts for all lockers from the looks of things.
How many miles on the locker?
How many miles on the locker?