The tranny on my 88 GL was pulled today for a clutch job and new seals.
When standing at the front of the engine, looking aft towards the back
of the van and at the front end of the crankshaft. I noticed a small
(3/4 in dia) device (for lack of a better term) sticking out of the face
of the crankcase in the upper left hand quadrant. This device was
circular and worn smooth from obviously rubbing against the back of the
flywheel for a very long time. This little thing was so loose in the
case I was able to simply pull it out with my fingers. Upon examination,
it appeared to have very small ribs and grooves so as to be driven into
the case and to be held there by the grip the ribs and grooves had on
the aluminum case. I THINK I found it in one picture in the Bentley but
there was no real explanation nor anything  about any repair. (sorry,
the Bentley is at the shop tonight so I have no reference page or image
I can reference). IF I had it right, the Bentley calls this a TDC
Sender. It obviously was in bad shape and in need of repair. But truly,
what is it, what does it do, and how does one repair the case where it
goes.It looks like the whole goes clear through and the unit acts as a plug.

Thanks,

Regards,

John Rodgers
88 GL Driver