Flywheel question. Re install or new? 1 tooth missing.

[yelcab1]

You can always push start it if the starter happens to land right on the missing tooth.

[jpnovak]

Just to clarify... as @pompadori showed pictures.

the 964 has two sets of teeth on the flywheel. One set is the timing gear teeth for the 60-2 pattern read by the crank sensor. This missing tooth is required for determination of #1 TDC and calculation of crank angle and spark timing. The second set is the starter ring gear.

In your case, you are missing a starter tooth and this must be replaced.

[camdon]

Originally Posted by proporsche

here is one on ebay for 150 ...here is the number
401492380636

Item number not working on e bay?

[camdon]

I got it now. SO I can just change that part?

[proporsche]

yup;-) and you will be all set;-)

Ivan

[camdon]

Sweet! Thank you

[jpnovak]

HOnestly, that flywheel surface is pretty much cooked. lots of evidence of friction surface deposition and chatter marks. I would consider to replace all of it. Yes, its expensive but so is double labor when your clutch chatters or slips and you have to replace.

At least get it resurfaced along with the pressure plate.

[manbridge 74]

I don’t think Porsche recommends resurfacing the dual mass flywheel.

I’d get a single mass - it really wakes up the car, is cheaper, and no real downside as recall but it’s been a few years since I did it per customer request.

[pkabush]

I agree with Jamie. That flywheel is hashed. That’s a bummer it can’t be resurfaced but, no way I’d put it back as is.

[Walt Fricke]

I had the rare 915 RSR ring gear - the ring was sculpted to remove parts of the ring between the bolt holes which are just dead weight, and the back sides of the teeth - away from where the starter gear engages - were beveled maybe 30 degrees to shed more weight.

I cried when I took the transmission off and found a tooth missing. Everyone I asked said there was no way to weld in a tooth. I hadn't noticed any starting issues. Maybe just one missing tooth doesn't prevent engagement even if things line up just wrong?

But that would mean more stress on an adjacent tooth, and in time it will break off. I bet if you end up in the two tooth gap you'll have to turn the key off, put the car in 5th, get out, push it a bit, and get back in to start it. Or always park on a hill. That could get old. There also isn't much room in there for a loose tooth to rattle around.

[proporsche]

i know you are saying the flywheel is a toast..but i do not see any crack or other structural marks.Most of the flywheels i have ever dealt with have some kind of marks....you cannot avoid that.But here is no damage at all.I would use it if it was my car.....
example here...

and herre


none of this is on Camdon`s flywheel...he would see it better...

Ivan

[MichaelSJackson]

That single bad tooth won't prevent the engine from turning over, but the jagged edge is going to chew on the starter gear each time it passes over. The starter gear has far fewer teeth so it will wear fairly quickly. Eventually it will get bad enough to not grab when it is matched up to the missing ring gear tooth. You might wonder how I know this?

If your feeling adventurous, you might smooth off the stub of the broken tooth, to minimize damage to the starter gear?

Michael S. Jackson
'78 SC with replaced ring gear

[Walt Fricke]

Michael - this is a post after my own heart, so to speak: something I didn't know (though we know why you do). And an interesting work-around possibility, at least if one is in a kind of bind short term.

[cabmandone]

Originally Posted by MichaelSJackson

That single bad tooth won't prevent the engine from turning over, but the jagged edge is going to chew on the starter gear each time it passes over. The starter gear has far fewer teeth so it will wear fairly quickly. Eventually it will get bad enough to not grab when it is matched up to the missing ring gear tooth. You might wonder how I know this?

If your feeling adventurous, you might smooth off the stub of the broken tooth, to minimize damage to the starter gear?

Michael S. Jackson
'78 SC with replaced ring gear

If you look at at the pictures you can see where there's rounding and signs of wear before and after that tooth.

[camdon]

I want to thank everyone for their input. I ended up getting one from a fellow forum member with only a few thousand miles on it.

I appreciate all of you guys and love this place.

[MichaelSJackson]

Hey Professor!

Nice to hear from you. I'm still pleased to read your posts when I get to.

Michael J.