Differential lock has always worked after a few seconds for 20 or 30
tries.
Yesterday, inadverdently had the knob out (on) and moved the van forward
about 20 feet straight on pavement.  Noticed the light came on, so pushed
in the knob.  Light went off. No problem.

Later got into the car to drive.  Light off.  Diff lock on.  Drove around
on dirt and grass, forward and back, mild turns, sharp turns,  a giant
CRUNCH signalled the return to non lock mode.

Drove around normally for a while.  On dirt.  Turn on lock. Light on,
lock on.  Push in knob.  Light off, lock on.  Drove around dirt and
grass, straight and with turns.  A small "crunch" signaled the return
to normal mode.

Since the switch detects the shaft position, it seems the servo shaft
is retracting enough to turn the light off, but is just hanging onto
the lock mode.

Bentley shows a shaft that almost looks like it has a flared surface
that could be grabbed.  Mine has no flare and looks like just a flat
shaft/sleeve.

Have searched the archives and the only relevant message was a suggestion
to put WD-40 on the shaft.

Thoughts?

Cheers, Tom Neal