Could I have the wrong flywheel?

[CurlyA6]

The partsman tells me that a '68 302 with a toploader could have either 157 or 164 tooth flywheels. The engine has been in the car for years (302) but the toploader (used) came with bellhousing and 157 tooth flywheel. Once assembled, for the past year it has started normally every few times, but then starter gear ground the flywheel gear a few times before starting normally again. I assumed that I installed the flywheel incorrectly,

Here is the question: since the car does start smoothly about half the time, does that prove the 157 tooth is the correct size flywheel? Would the 164 tooth larger flywheel prevented the starter from even mounting and engaging? Or should I have been running the 164-tooth flywheel all along?

Thanks.

 

[CurlyA6]

More info

I've just read some of the old entries on this website about the difference between 289 and 302...most say that only the crank and rods are different. Does anyone know why, then, that the 68 289 lists in the parts books with a 157 tooth gear flywheel and the 302 lists 164 tooth?

Thanks.

 

[Loup-garou]

It's not so much 289 vs. 302, but a matter of which bellhousing and motor plate you're using. I'm going from memory here, so feel free to do more research to verify this, but the Windsor V8's with a 10-1/2" clutch use the 157 tooth ring gear while cars with the 11" clutch use the 164 tooth ring gear.

There's a website called Mustangtek.com that has pictures of the respective bellhousings and shows how and where to measure to determine which you have.

 

[PoppyMod]

The partsman tells me that a '68 302 with a toploader could have either 157 or 164 tooth flywheels. The engine has been in the car for years (302) but the toploader (used) came with bellhousing and 157 tooth flywheel. Once assembled, for the past year it has started normally every few times, but then starter gear ground the flywheel gear a few times before starting normally again. I assumed that I installed the flywheel incorrectly,

Here is the question: since the car does start smoothly about half the time, does that prove the 157 tooth is the correct size flywheel? Would the 164 tooth larger flywheel prevented the starter from even mounting and engaging? Or should I have been running the 164-tooth flywheel all along?

Thanks.

Hi,
The difference in teeth count is not, mostly likely, your issue. Yes, there are reasons for when to use either a 164 or 157 tooth flywheel/flex-plate, but, this has to do more with imbalance bellhousing size, year of engine, auto tranny size/model etc.
If your engine has run fine for the "past year" as you stated, then something else is going on. When you state "but then starter gear ground the flywheel gear a few times before starting normally again." Do you mean, at times, the starter failed to engage the flywheel properly? Be more specific. You might remove the starter and look at the starter gear for any signs of unusual wear and while at it, slowly rotate the engine noting the condition of the teeth on the flywheel.
Good Luck!

 

[zookeeper]

Totally unrelated, but still worth a mention: did you know that 6-cylinder flywheels will bolt on a 289? Do you also know that it creates a horrible shake? I bought what I thought was an 11" flywheel for a 289/302 at a swap meet once, had it ground and installed it only to learn it was from an inline 6. Not my best day...

 

[CurlyA6]

Loup-Garou: Thanks for the steer to MustangTek. Very helpful.

The plot thickens! The bellhousing casting number is C5DA-6394-A, which seems to confirm the 157 tooth gear and 10.5" clutch is appropriate. Good so far.

The rebuild guy wasn't exactly precise 20 years ago when he took my original 289 core and wrote on the receipt "replaced with a '68 302." Turns out the block numbers are C9OE-6015-C, which my secret decoder ring tells me is a '69 351W (not a '68 302)...but I understand that makes no difference here, so still good.

Not that it matters, but the Toploader numbers are C8AR-7006-D W2, which I believe could be a '68 289 or 302 Mustang (among others), and the tranny tag is RUG M3, a '69 Mustang 390, 28 spline, wide ratio. Likely still okay.

Here is where it gets messy. I think you are on to something with the motor plate. The starter was difficult to get into place when I swapped it, and I just wrote that off to the manual setup being different than the automatic I was used to (I did verify the two starters I've tried are for the manual). I did eventually mount it by hand, but it wasn't easy, and now it's stuck in the motor plate...I unbolted and tried to wiggle and tap it out, but it is solidly connected (no corrosion, just stuck). Could be that the motor plate is close, but not correct? I'm contemplating, once I get the starter out, "bluing" the starter nose and putting it back in it's place, then trimming the motor plate starter hole to make mounting the starter free from binding. Bad idea?

Thanks.

 

[CurlyA6]

Poppy Mod,

Thanks for the reply. I'm glad to hear that inappropriate tooth count is not the problem. Happy to rule it out. If I understand correctly, putting a smaller flywheel with the 157 gear in a 164-gear sized bellhousing is possible, but would not result in my problem. Instead of occasional bendix gear grinding, with that combination of flywheel and bellhousing, the starter gear wouldn't even connect with the flywheel gear and the motor would never turn over...correct?

So if the flywheel is the correct size and gearcount for the bellhousing, and the starter is verified for the manual transmission, it leads me to believe I have an alignment problem.

Your guess (above) is exactly correct. After several "normal starts", let's say every fifth or sixth time, the bendix drives the starter gear and a horrible grinding noise is made, and the engine is not turned over. It seems the starter gear occasionally doesn't mesh with the flywheel gear, and instead grinds the flywheel gear without cranking the engine over. It may do that three times in a row (now that I know the flywheel gear is ruined, I've experimented more trying to eliminate variables) but eventually starts normally.

I've pulled the starter an looked inside the bellhousing. Sure enough, the "new" ringgear is now 30 percent damaged teeth. Looks like only the side closest to the starter motor, leading me to believe the starter gear isn't extending fulling into the bellhousing. I've tried two starters (before there was so much flywheel gear damage) with the same results.

During the swap (a year ago) from C-4 to Toploader, I replaced the old, used flywheel gear after verifying the original was 157 tooth. I'll check to see if I installed the flywheel gear incorrectly, perhaps not placing it fully on the flywheel to the shoulder. If that's not it, I suspect Loup-Garou's thought about the motor plate may be causing a misalignment of the starter.

If not, I'm stumped. Any more thoughts you may have would be most welcome.

Thanks.

 

[CurlyA6]

Zookeeper...that sucks. I'll remember to look out for traps like that in the future. Thanks for the info.

 

[PoppyMod]

Hi,
I think at this point, as you mention, maybe you didn't install the flywheel correctly, rotate the engine slowly looking for signs of any slight wobble? Perhaps, using the edge of the starter opening as a guide. If not, with the difficulty you mentioned in retrieving the starter, it's being correct for the application is suspect. Especially, when all of the different year parts are noted. If none of this is revealing, then, I guess you have no choice but to pull the tranny do an inspection of the block plate, flywheel integrity etc. Also, you have the added benefit of installing the starter and noting any alignment issues with the flywheel from the backside.
Good Luck!

 

[horseballz]

I am not certain of the differences or rhyme or reason between the different tooth count flywheels, but have read several places that the difference between the two main starter mounting configurations is not just a simple as automatic vs. manual transmission. From what I've read there is basically a "long" snout and a "short" snout unit and under certain circumstances/conditions one may kind of work in place of the other, but not properly. It sounds possible that you may have a "long" snout application with a "short" snout starter. Go to the parts store and ask to see an automatic and a manual starter and set them side by side and you will see that the difference in length is not very much. I could be wrong, but this is what I've read. I have certainly seen manual cars that require an "automatic" starter and vice/versa.
HTH,
Gene

 

[CurlyA6]

PoppyMod,

No signs of flywheel wobble. I'll drop the tranny today and see what is evident looking into the bellhousing from the tranny hole. I think I'll also pull the flywheel, then mount the block plate, bellhousing and starter back on the engine. This will allow me to look in from the tranny hole and see if I can detect the block plate making the starter misalign. I may be able to scribe the blockplate from the tranny side inside the bellhousing in case I have to trim the plate opening a bit to make mounting the starter possible without binding. I'll let you know how that turns out.

Thanks.

 

[CurlyA6]

Gene,

Is snout length the only difference between the starter for a manual and automatic transmissions? If so, comparing them sounds like a great idea. I'll check it out.

Thanks.

 

[PoppyMod]

Gene,

Is snout length the only difference between the starter for a manual and automatic transmissions? If so, comparing them sounds like a great idea. I'll check it out.

Thanks.

I'm not so sure that's a difference. I'm running the same starter on my T5 as I did with my C4, so, the tranny difference is not going to be the issue, in itself.
I'm thinking you're going to see something out-of-whack when viewed from the opposite direction.
Good luck today!

 

[CurlyA6]

Frustrations abound. The flywheel is now out of the car and the ring gear removed from the flywheel. Closer inspection of the ringgear shows that the wear pattern is only on the half of the tooth surfaces nearest the motor. I thought that meant that the starter gear was not extending all the way into the bellhousing, but I'm told that this wear pattern is about right.

So, I'm left with only the binding/alignment of the starter as a cause for the ring gear damage. I placed the motor plate precisely on the bell housing, then placed the starter motor in its spot. The starter bolt holes in the starter, the motor plate and the bell housing all line up and the starter slides in without binding.

In the car, however, with the flywheel in place, the starter will not smoothly slide into place and I have to start the bolts, tightening them to force the starter the rest of the way in. On the very nose of the starter, there is a small patch of freshly ground metal, as if the ring gear is grazing the starter nose point. If I can figure out how to load pictures, I'll post them next.

I hate the thought of putting the car all back together only to hear that grinding noise again. Other than replacing the ring gear, I haven't found anything to fix...I don't think I've addressed the problem.

My plan is to grind a little bit of metal off the motor plate starter hole, allowing the starter to mount just a hair further from the crankshaft axis. My hope is that this will allow the starter to be put into place without having to be forced by the starter bolt tightening described above, and that in turn the starter will not be misaligned.

My question is by enlarging the starter hole in the motor plate slightly, am I inducing another problem? Does the starter plate hole snugly hold the starter in position, preventing flexing, or do the starter bolts hold the starter in place during starts? Just don't want to carry out my "good idea" and cut the motor plate only to find out later that was a dumb idea.

Thanks.

 

[horseballz]

Sure sounds to me like you have a long snout starter where you need a short snout starter.
Gene

 

[CurlyA6]

Here are three photos to show the problem area. The first shows just how close the starter is to the flywheel gear (bellhousing off...starter mocked up in position) and how little the nose of the starter extends past the ringgear.

The second is a closeup of the first. The third photo shows where the ring gear (I think) has been nibbling away at the starter nose.

Do any of these photos help show if I have the "wrong snout" starter or if I should grind a bit of the motor plate to allow the starter to sit just a little bit further from the starter ring gear?

Thanks.

 

[horseballz]

Looks like I was backwards on my guesstimate. You may have short snout where you need a long snout. If you could have a long & short (manual & automatic) handy at the same time you could test fit to be certain. If need be, you could buy the opposite of what you have (or both long & short) and return whatever wasn't pertinent. Looks like the one you have is pretty close to whooped. Seeing those pics is very enlightening. They show the geometry of the setup which explains a lot of the why and wherefore.
Gene

 

[dennis112]

You shouldn't need to modify correct factory parts.

Have you tried a Ford 4 speed toploader specific starter yet? The snout is different than one from the automatic. Both the 157 and the 164 tooth starters are the same--but you need one specifically for a 4 speed. If nothing else, take yours down to your local Advance Auto (ours stocks them) and do a comparison before trying to make yours work. Specify a 68 Mustang with a 302 and a 4 speed toploader.

 

[CurlyA6]

I'll do that. I asked the parts man for a manual starter when I did the swap from automatic to manual during the restoration (over the last 10 years). Once I got the car on the road again (last year) and the starter trouble was evident, I went back to the same place and tried another manual transmission starter. Perhaps I'll try a different parts supplier and see what his starter options are.

Thanks.

 

[pabear89]

Here are three photos to show the problem area. The first shows just how close the starter is to the flywheel gear (bellhousing off...starter mocked up in position) and how little the nose of the starter extends past the ringgear.

The second is a closeup of the first. The third photo shows where the ring gear (I think) has been nibbling away at the starter nose.

Do any of these photos help show if I have the "wrong snout" starter or if I should grind a bit of the motor plate to allow the starter to sit just a little bit further from the starter ring gear?

Thanks.

From your pic's posted, you have the wrong starter.
It is a short nosed automatic starter, it will never contact the flywheel correctly.
Some minor grinding to the blockplate opening to allow the starter install may be required, but wait till you have the right starter motor before doing it.