busted flywheel dowel pin

[paanta]

I've got a flywheel dowel pin sheared off just below the surface of a single mass '80 633csi flywheel going into my E34 535i. I've not had to deal with this one before...

1) Do I _need_ to fix it? Can I get by with 2 out of 3 flywheel dowel pins? Yeah, I think I know the answer...

2) Best way to extract it? I could try drilling it out, but the surface of the broken part isn't level, so I'd risk nicking the flywheel. I could punch it out, if I knew how to get the starter ring off the flywheel, but I don't.

3) Best way to install a new one? Can it be hammered in, or do I need to get it pressed in by a machine shop?

[whiskychaser]

I've got a flywheel dowel pin sheared off just below the surface of a single mass '80 633csi flywheel going into my E34 535i. I've not had to deal with this one before...

1) Do I _need_ to fix it? Can I get by with 2 out of 3 flywheel dowel pins? Yeah, I think I know the answer...

2) Best way to extract it? I could try drilling it out, but the surface of the broken part isn't level, so I'd risk nicking the flywheel. I could punch it out, if I knew how to get the starter ring off the flywheel, but I don't.

3) Best way to install a new one? Can it be hammered in, or do I need to get it pressed in by a machine shop?

They are locating dowels so the clutch may be a real pig to fit if you dont replace the missing one. Unless you are a whizz with a gas torch forget taking the ring off. Give it to a machine shop. They will come across this all the time and probably charge peanuts to do it. You know the job is done right and you dont have to worry every time you let the clutch out:D

[paanta]

They are locating dowels so the clutch may be a real pig to fit if you dont replace the missing one. Unless you are a whizz with a gas torch forget taking the ring off. Give it to a machine shop. They will come across this all the time and probably charge peanuts to do it. You know the job is done right and you dont have to worry every time you let the clutch out:D


I managed to get it out.

For future reference: cut it off with a dremel where it pokes out between the flywheel and gear ring. Punch it through until it comes almost in contact with the gear ring. Cut it off again between the ring and flywheel. Repeat as necessary.

I assume the new one can be hammered in fairly easily?

[paanta]

Next question: http://www.realoem.com/bmw/diagrams/a/o/2.png

What's the point of part #6? Why is one of the flywheel bolt holes over-bored?

[gale]

That's an alignment sleeve that indexes the flywheel to the crank. One of the holes in the flywheel and crank is slightly oversized. The crank and flywheel were balanced as a unit at the factory and the sleeve assures it will be assembled in the correct orientation.

[paanta]

I assume, then, that the factory balancing is irrelevant once you've replaced your flywheel with a new one?