Audi tape deck, complex mechanical question

[BOEING377 <BOEING377@aol.com>]

I am trying to repair my broken Audi Blaupunkt Gamma (non Bose) radio-
cassette head unit.  I have fixed the intermittent on-off switch by
painstakingly prying open the combo vol control, on-off, and station select
control unit and cleaning the contacts.  The tape transport problem is
baffling me.  One gear, which operates the eject mechanism, appears to have a
portion of its teeth missing, but on closer inspection it looks as if it may
have been molded that way (i.e. made with teeth only going partway (about 290
degrees) around the edge and a gap with an indentation towards the center on
the remainder of the periphery).  If it is a broken gear, I cannot find any
pieces inside. The transport was totally non-op.  Now, by remounting the
aforementioned wierd gear so that it meshes (was previously not meshing with
anything) I have it playing and reversing, but there is a ratcheting sound
like a gear not fully meshing while it is playing and it will not eject a
tape.  The "weird gear" also has a track cam near the center and a slot
further out towards the edge within which a guide pin moves.  The cam and slot
are engaging the cam follower and pin OK. I know I should just buy a rebuilt
unit, but now it is an emotional man vs machine issue and I can't admit
defeat.  Any suggestions?  Is my eject gear broken or are they made this way?
If its broken where are the pieces? All help deeply appreciated.