The first ring gear was tore up using my stock starter. My initial investigation pointed to exactly what you were saying about engagement but then I have the same thing happen with the new starter. I confirmed alignment with the teeth on the new stater. I have a habit of throwing things away too soon. The original starter ring and starter are long gone.

I just checked static timing of both distributors. They are lined up properly. Once I get it running again, I'll have it checked with a light.

Here is a picture of my ring gear failure:

http://forums.pelicanparts.com/uploa...1340151513.jpg

This is from a higher compression race engine using a Hi Torque starter.

The starter checked out fine in all tests. It extends the appropriate amount, It retracts quickly and completely. The pinion gear is correct.

I installed a new ring gear sourced from Parts Heaven and the problem, so far, has not returned.

Regardless, my next ring gear is coming Kennedy Engineering.

Scott

As I stated in my first post, measure! All ring gears do NOT have the same O.D. Dan

[QUOTE=winders;6812741]Here is a picture of my ring gear failure:

http://forums.pelicanparts.com/uploa...1340151513.jpg

check out the witness mark on the third tooth from the right. the one still standing. half way in and toward the tip. just like how the others broke.

[QUOTE=john walker's workshop;6813384] I'm no metal expert but winders and mine both look like the metal "snapped" off as if it were too brittle. I've seen old ring teeth worn away from an improperly engaging starter. The key word here is "worn" down at contact and the tooth still didn't break off. So far I've heard from five different people with similar problems and the only thing they changed was the manufacturer of the ring gear. One even went with a used "proven" one and problem was solved. Thanks for all your input everyone, I'm ordering a new ring from KEP (they gave up on OEM rings years ago). Looks like it'll be 2 weeks to get here (Canada customs:() and once I install, I'll take some measurements, check timing and cross my fingers. I'll keep you updated. I'll be missing my trip to Calabogie in July but should be back on our local track for August.

oops, third tooth from the LEFT. guess i wasn't completely awake at 5am.

My car ate a couple starter ring gears in about 200 starts before we fixed it by switching starters.
I don't think the issue is the same as the OPs, but I thought it's worth mentioning here.

You can see from the below that my ring gear teeth also didn't snap, suggesting they were not as hard as the other examples so far:
http://forums.pelicanparts.com/uploa...1340206185.jpg

Hayden has a good writeup on his blog with full details:
« Last weeks carrion….. Welcome to Windrush Evolutions - WEVO Blog

Basically the 13:1 compression was too much for the stock or standard high torque starter, forcing the teeth out of good contact with the ring gear. However Hayden managed to figure out that the 993 tiptronic starter is a much better design and is more than strong enough. It shouldn't really be required for the OP, but for winders and others running high compression motors this could be a good solution.
http://forums.pelicanparts.com/uploa...1340206226.jpg
We made this change a couple years ago and we haven't had an issue since. As a bonus the tip starter is a useful 3 lbs lighter than standard.

Any theories as to why it would break off teeth on either side of that tooth?

That's exactly what I would expect to see if the starter or alignment was off. Thanks for the info.

I think John Walker is saying that the gear on the starter hits the flywheel to high and too far back. Is there any way to observe how those gears mesh? Can you put blueing on the gears and see the contact points?

Hi Rick,
Wouldn't the teeth just wear down like the ones pictured in Petevb's post rather than shear off? I was able to confirm alignment back and forth. I'll take some measurements when reinstalling the KEP(Kennedy Engineering) ring to confirm if it's engaging at the right height. Petevb's post certainly makes me think my rings were too brittle.

Peter,

Will the 993 starter fit on a 915 with a 3.6L?

Scott

Not sure. I'd think it would, but...

http://forums.pelicanparts.com/uploa...1340220860.jpg

Old and brittle versus new and brittle http://forums.pelicanparts.com/support/smileys/baby.gif

Well, I'm still waiting for the new starter ring from KEP. It left California June 20th.
Has anyone here heard of putting a thin coat of MolyKote on the stater ring. I was told that a thin coat of lubricant will help ease engagement forces. Any thoughts?

I,m sure you could lightly grease a dry ring gear but it should,t be needed. diesels with 18:1 compression use the same style ring and don,t suffer this repeated type failure . I suspect mis alignment somehow.

This exact problem just happened to me today in fact... I installed a new OEM ring gear that I purchased from pelican and it failed within 20 starts. I'm using a high torque IMI starter. I also called KEP and ordered a genuine Porsche unit. Here's to hoping that fixes it.

Man that blows. May I ask why you needed a new one in the first place? How old was the one you just replaced? My original starter ate my original ring in one spot at 98k miles. I just installed pelican mini starter and ring and you guys are freaking me out!