why don't these line up?

[Phil Payne]

> Question is, when I was setting the cam timing to the crankshaft, I
> encountered an odd situation.  In the Bentley manual, it says that the #1
> cyl is at TDC when the 0 on the flywheel is in the middle of the
bellhousing
> window on the transmission.  It also notes that the front pulley set (on
the
> crank) has a mark that should line up with the "wing" on the oil pump
> housing (this is a metal piece that sticks out near the edge of the oil
> pump).  When my flywheel is in the correct place, this mark on the front
> wheel is not in the proper position.  It is lined up instead exactly in
the
> middle of the idler pulley bolt.
>
> I pulled the #1 spark plug, and stuck a screwdriver in to check when
actual
> TDC was.  The flywheel mark is correct, so I know the flywheel is not in
the
> wrong position.  So, the question is, why is my front pulley in the wrong
> orientation.  There is only one way to fit it on, as it is keyed to the
> crankshaft, and the crank can't twist so that It would be wrong like this.

The pulley mark should be ignored - it is provided only as a check mark for
original installation in the factory.

a) It can and does move by few degrees.  The harmonic damper (pulley) is
actually pressed together and can rotate within itself.

b) The pulley/harmonc damper assembly comes apart and can be reassembled in
multiples of 90 degrees out of alignment.

The upshot is - ignore the pulley.  The factory microfiche has a STRONG
caution to this effect. The flywheel has the only reliable mark.

Your check of actual TDC using the screwdriver was exactly the right
response, BTW.

--
  Phil Payne
  http://www.isham-research.com
  +44 7785 302 803