Hi,

There's a bit of a rationale for having the woodruff key on the
crankshaft and pump, but not the camshaft. The camshaft and crackshaft
are both fixed in position w.r.t to each other, while the pump can
be rotated. (as is done in the timing procedure.) Hence, to adust
the cam timing a pulley has to be slid a bit. This is the procedure
described in the manual where a reference plate is inserted in the
slotted end of the camshaft and then balanced straight with feeler
gauges to the two reference surfaces on the head.

In  practice the camshaft pulley doesn't slide if torqed right, while
people who have dropped or forgotten the woodruff key on the crank
pulley have found that it does slide there...

If you like more info search the list archives for the vanagon
and various other Diesel VW mailing lists.

Best,
Martin

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   Date:        Tue, 29 Apr 2003 13:58:49 +1000

   Hi Martin,

   Hope you don't mind me contacting you. Got your email from a VW Diesel
   page and thought you might be able to answer something that mystifying
   me.

   I'm restoring a '78 Rabbit (Golf) Diesel for my 17yo daughter. It needed
   a new head, so I bought an engine out of an '80 model for $90. (The head
   is perfect!)

   When I removed the camshaft gear from my '78, I noticed both the gear
   and the tapered end of the camshaft have a slot for a woodruff key, but
   there was no key installed. Also the camshaft gear has a small slot cut
   into the back of one tooth, obviously to aid timing, although there's no

   mark on the head itself.

   When I removed the camshaft gear from the '80 engine, although the
   camshaft taper still has a slot for a key, the gear itself has a
   perfectly smooth taper fitting and has no timing slot either (other than
   that it looks identical to mine - neither have any part no. on them).
   Obviously, it's held on to the camshaft purely by the taper and torque
   of the end bolt. (As obviously my '78 one was, anyway).

   Did VW have a change of heart and intended a key to be used initially?
   No key does mean that the valve timing is not restricted by having to
   move a whole tooth position, but I've never known a camshaft that wasn't
   keyed. It worries me to think of the damage to the engine if the gear
   slipped! (Even the fuel injection pump gear is keyed, and you can turn
   that over by hand - not like cams/valves etc.!)

   I must confess, both the VW Workshop manual and Haynes manual show no
   sign of a key in their exploded diagrams, and actually tell you to
   loosen the camshaft gear bolt and knock the gear off when fitting a new
   timing belt - which speaks of no woodruff key.

   Thanks for any info (and assurance) you can give me that my cam gear
   won't slip as soon as I start the engine.

   Robert

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