Flywheeel Teeth

**Bwmurph** · 02-04-12, 10:30 AM

Is there any way to tell how many teeth are on the flywheel without dropping the bellhousing and counting them ? Can you tell by how many teeth are on the starter ? How many different Flywheels; I know of two (153 and 164, teeth I think), but don't know how to tell which is which and where and why they were used.

Any help is appreciated,

Bernie O.

**Tom Bryant** · 02-04-12, 04:29 PM

I would think by application. What car/engine are you talking about? Is it original?

Tom

**Bwmurph** · 02-05-12, 09:06 AM

Tom,

None of it is original; it's a '59 with an early crate motor and a Muncie M-20.

It's going to come apart (again) in the next few days, so I'll just count the teeth. Reason is it looks like I'm going to go with a Keisler transmission and they need to know the flywheel teeth count to properly quote and I was hoping to get it in the works. It'll just wait until I can get an accurate count.

How many ifferent flywheels are there anyway ?

Thanks,

Bernie O.

**Tom Bryant** · 02-05-12, 10:44 AM

Unfortunately the GM parts book doesn't give teeth count, just application. I was looking on Summit and I see 168 and 153. Mostly 168. I didn't see 164 but I was looking at early small block applications (283, 327) where the starter bolts to the bell housing. Your newer crate engine would be a block mount starter. I'm also confused as to what was used with what and the applications on Summit, which are usually a very good reference, are overlapping.

I'd like to do the Keisler trans deal too one of these days if I ever get the '59 back on the road.

Tom

**Bwmurph** · 02-05-12, 11:19 AM

Actually my starter does bolt to the bellhousing. I just dug through all my old paper work - it's a very early crate motor (purchased in 1995) with P/N 12356644. Also found the receipt for the Flywheel - it's P/N 10105832.

Is there a place where I can reference this P/N and find the tooth count ? Can I just call the Parts Dept at the local Chevy dealer and have him tell me the tooth count ?

Regarding the Keisler - it wsa in the long range plans for the '59, but since I blew the Muncie a few weeks ago it got moved up in the program. Not gong to be doing much elst to either the '59 or the '71 this year once this is finished !

Bernie O

**Tom Bryant** · 02-05-12, 05:45 PM

I searched Pace Performance Parts and came up with this.

Pace Performance

Looks like your flywheel has had a number change but appears to be a 168 tooth flywheel.

Tom

**Bwmurph** · 02-06-12, 12:08 PM

Boy, I'm really confused now. I'm ALMOST sure I have a 14" clutch; at least that's what I have circled on the old paperwork I found with the receipts for the flywheel. And my started definitely bolts to the bellhousing (aluminum b/h, not the correct cast iron for a '59). I guess I'll find out for sure once it gets apart.

I'll let you know how the install with Keisler goes and how much I like once it's back on the road. (I better like it a LOT for the $$$ I'll be spending)

Bernie O.

**JohnZ** · 02-06-12, 08:30 PM

If your starter has horizontal bolts into the front of a GM bellhousing (not vertical bolts into the starter pad on the block), you have a 14"-diameter 168-tooth flywheel; that's the only size flywheel that was ever used on C1's. If it had a 12-3/4"-diameter 153-tooth flywheel, the starter wouldn't engage the ring gear. The large flywheel used originally on C1's (casting #3729004) was drilled for a 10.4" clutch, but the later large flywheels used on '66-'74 427 and 454 big-blocks and '69-up small-blocks was drilled for an 11" clutch. 11" is the largest clutch ever used in a Corvette.

**Bwmurph** · 02-07-12, 03:14 PM

John,

Thanks for the reply.

So if I understand you correctly I DEFINITELY have a 14" - 168 tooth Flywheel. The starter definitely has horizontal bolts through the b/h with two bolts going through the starter into the b/h and one bolt going through the b/h then through the starter and into the block.

Again, if I understand correctly, I could have either a 10.4" or 11.0" clutch disc, both of which COULD fit this flywheel, correct ? Nothing in the drive train of this car is original so it was pretty much mix and match when I took it all apart and freshened it up back in 1995- 96.

I will make sure what size the clutch disc is when I get it apart and go form there, but at this point I can safely tell the Keisler people that I have a 168 tooth flywheel to get them to quote me on the transmission kit.

Thanks,

Bernie O.

**JohnZ** · 02-07-12, 03:52 PM

Originally Posted by Bwmurph

Again, if I understand correctly, I could have either a 10.4" or 11.0" clutch disc, both of which COULD fit this flywheel, correct ? Nothing in the drive train of this car is original so it was pretty much mix and match when I took it all apart and freshened it up back in 1995- 96.
Bernie O.

If the flywheel is the original GM (casting #3729004), it's drilled for (and will only accept) a 10.5" clutch; the later GM 168-tooth flywheels were drilled for an 11" clutch (the bolt hole patterns are different for 10.5" and 11" clutch pressure plates). Or, it might have an aftermarket flywheel that's drilled for both patterns.

**Bwmurph** · 02-08-12, 11:59 AM

John,

Its definitely not an aftermarket piece; I bought it right from GM Parts Dept when I bought the crate motor. I also seem to remember having to take a flywheel back to dealer because it was the wrong one or wouldn't fit or something, but I can't recall the exact circumstances at this time.

I guess the best thing for me to do is actually measure the clutch plate when I get it apart.

Thanks for your help,

Bernie O.

**Bwmurph** · 02-09-12, 11:46 AM

Well......... the saga continues with this car. It seem now that I was right all along - the clutch is bad !! After taking it apart and not really seeing anything wrong with the clutch (I even took it to a local NAPA store and the guy there said it looked fine), my mechanic was SURE it was the ring & pinioin. Took that apart and there's nothing wrong with that either ! SO.... it MUST be the transmission -- took that out, pulled the side cover off and everything in there looks just like it's supposed to (it was a little low on gear oil, though).

So my mechanic starts looking at everything again and when he gets to the clutch he notices that the center hub where the trans shaft /splines go through the clutch disc looks a little strange. You have to look hard, but you can see where the hub has several small tabs that interlock on the clutch disc and these tabs have actually rotated out of the tabs some (wish I had pictures of it). He took the hub section apart and there are little flat springs (don't know the correct terminology) and several other spacers/washers in there that were all chewed up and broken. The rest of the clutch disc is in like new condition and you really had to look at it to notice that the hub had actually rotated on the disc. Curt (the mechanic) has drag raced cars since the '60's and he said he has never seen a failure like that before; I know I sure haven't.

So now I have a dilemma -- I was all prepared to bite the bullet and put the Keisler 5-speed in the car and now it seems all I need is a new clutch (and maybe re-surface the flywheel). I may still go with the Keislar as that was the long-range plan for this car anyway and I had myself all prepared for the hit to the wallet -- I'm waiting for the quote fgorm Keisler and if they don't knock my eyes out with their pricing I'll probably pull the trigger on the conversion.

Bernie O

**JohnZ** · 02-10-12, 06:00 PM

Originally Posted by Bwmurph

So my mechanic starts looking at everything again and when he gets to the clutch he notices that the center hub where the trans shaft /splines go through the clutch disc looks a little strange. You have to look hard, but you can see where the hub has several small tabs that interlock on the clutch disc and these tabs have actually rotated out of the tabs some (wish I had pictures of it). He took the hub section apart and there are little flat springs (don't know the correct terminology) and several other spacers/washers in there that were all chewed up and broken. The rest of the clutch disc is in like new condition and you really had to look at it to notice that the hub had actually rotated on the disc. Curt (the mechanic) has drag raced cars since the '60's and he said he has never seen a failure like that before; I know I sure haven't.

The little spring segments are the "Marcel" portion of the clutch - they are actually slightly curved, fit inbetween the friction material and the hub spiders on both sides, and they "cushion" clutch engagement; race clutches don't have the Marcel elements, and that's why they're "grabby" when they engage.

MarcelSpring.jpg
LuKclutch2.jpg