Intermediate shaft gear wear

[Rich76_911s]

Hey everyone I just had a couple of questions about a 1989 3,2L engine I am beginning to rebuild.

1. What would cause teeth from the intermediate shaft gear to all have wear (or broken pieces as seen in the photo) on the flywheel side of the gear? Every tooth has wear or the edge or is chipped off. I bought this engine used and have never run it so I don't know what happened to cause the failure. Do you have any ideas? Is it possibly a failed chain tensioner?




2. I purchased a complete intermediate shaft off of a pelican a long time ago a lot of the teeth have some pitting and slight wear. Do you think it would be best to just purchase a new gear. Pelican has them available and at $200, it seems like a part that is that deep in the engine is something you don't want to be rolling the dice with. Would you agree with that.

3. I have been working on cleaning my parts like the chain tensioners, oil pump, idler gears, and miscellaneous bolts lately. Using 3M scotch pads with mineral spirits and denatured alcohol. However all of them still have residue on them that is not coming off with any amount of elbow grease I put into it. Is it worth it to pick up a small ultrasonic cleaner like this; or do most people take these parts to the machine shop to get cleaned?
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91957

Rich