1/2" tapedrive hardware problem

[Loki Jorgenson rm 421]

Now don't shy away because the word hardware is part of the subject title.
I have a simple problem which I'm *sure* someone has solved before and can
advise me on.

We have a SUN supported CDC 92181 series 1/2" tapedrive.  It has a
'push-in/pop-out' reel hub-lock.  If you know the machine, I trust you
know what I'm talking about.  With increasing frequency (almost once for
every full reel of tape now), the hub-lock pops out during back-ups,
ruining the dump, forcing one to start over...... only to have it pop
again.  The result ...... very few level 0 dumps after many tries.  

Is there a simple (or ridiculously complex) cleaning or adjustment
procedure to correct this?

Thanks in advance,

Loki Jorgenson			node:  loki at physicsa.mcgill.ca
Physics, McGill University	fax:   (514) 398-3733
Montreal Quebec CANADA		phone: (514) 398-6531