VW used to have a "computer diagnostic unit" in the dealerships that was
supposed to tell  what was good or bad with the basic engine settings..Never
worked worth beans..The sensor was a tdc part of that system..toss it..
Daryl of AA Transaxle
(425) 788-4070
aatransaxle.com
86 Syncro Westy
Zetec in the trunk
----- Original Message -----
From: "John Rodgers" <inua@CHARTER.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, March 16, 2009 5:55 PM
Subject: Manual Tranny R&R - mysterious part

> 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