I just replaced the water pump on a 1989 760 turbo. Reassembled and ran fine but stopped after a few seconds and wouldn't start again--seemed to have no compression. A bit of troubleshooting revealed that it had jumped timing by nearly 90 degrees. The cause, I think: when I removed the timing belt cover during the water pump replacement, the back timing belt cover had disintegrated, and fell into many pieces. I retrieved all I could, but I think some debris remained in the lower cover and became fouled in the gear while the engine (briefly) ran.

So I read the procedure in Chilton's which said to remove the top and bottom front covers. Top cover, no problem. The lower cover seems to require the removal of the main crankshaft pulley although the procedure makes no reference to that.

Is that correct, and if so, how difficult is it to remove the pulley? Is a puller required.

As a stopgap I wondered about cutting an access hole to access the mark on the idler gear, then taping back over it...