Car acting like flywheel's loose, but it's not?

[ArtemisI6]

1967 Mustang with a 200ci and a 3spd

I just finished valve seals on it yesterday so I thought I'd take it out for a ride. It has some somewhat nasty clutch chatter that can be avoided depending on how you manipulate the clutch. It takes some getting used to but my girlfriend and I can both easily get the car moving (even on a hill) without the thing chattering, so since a new clutch costs so much money and the disc itself is in good shape I haven't replaced it. I don't know if that's related to my issue but I figured I'd mention it.

Anyways. I went to start it today and the starter ground against the flywheel teeth. It has never done this before. This was after it being parked maybe five minutes. Before this I had started it and driven it about three miles. I accidentally chattered the clutch pretty badly at one point and I thought I heard a pop. I also took a turn a bit hard over some potholes and I thought I heard some other pop noise. I can't describe either of these events better than that because I'm not even 100% I heard them, or that they're related, or that they even came from the car itself. Again, mentioning it just in case.

So anyways I went to start it and the starter bendix ground against the flywheel teeth. It still managed to crank over the motor, however. I had to make about three more stops before I could get it home, each time starting it, it would grind like this. The starter has less than 2,000 miles on it so I figure it's not the bendix failing to pop out all the way. I figured maybe I failed to torque the flywheel bolts enough (enough I did it to 80ft/lbs) and the flywheel bolts must've gotten knocked a little loose by the occasional clutch chatter.

The first thing I checked was if the starter was loose because I had this happen with my truck once, and it was because the top bolt on the starter had worked itself loose. Neither bolt was loose at all. I figured this narrowed it down to the flywheel. So when I got it home tonight I set to work pulling the transmission.

I have everything out of the car and not a single flywheel bolt is loose in the slightest. The flywheel's teeth are half chewed off on one side of the flywheel and all of the teeth on the starter's bendix are halfway chewed off, which I'm assuming is due to today's events.

What the heck else might've caused this?! I am really fed up with this car right now. It's not worth the stress it's caused me in the past year. I'm going to have to replace the already-new starter and the newly-machined flywheel now. How can I prevent this from happening again? I can't even think of what it possibly might've been besides the starter beginning to prematurely fail.

 

[66 Fastback]

Not sure about the starter failure.
With regards to the chatter, did you replace the pilot bushing?
Was the throwout bearing replace and is the input bearing retainer in good shape with no burrs etc so that the clutch engages smoothly?

Also was the transmission bellhousing made up or bolted all the way tightly to the engine block. If something is loose there, you can have an alignment issue with the transmission / clutch as well as the starter.
I mhave heard of some folks checking to see if the bellhousing is centered with respect to the crank. I have never done that, but some cars have adjustable dowell pins to provide better alignment.
Doug

 

[Axle Roads]

I'll take a wild guess that the gear on the starter's bendix drive was not up to original manufacture specs. The teeth were very slightly mis-calibrated, progressively breaking down each time you started your car. It could have been a manufacture SNAFU. Study the damage more closely or compare the teeth pattern to another wheel to confirm. I'm not going on experience here, I'm just speculating.

 

[MPGmustang]

pop??? did you check for cracks on the BH? block bolt holes?
i'm not experienced in this either but i'd check to see if you need a FW shim, .050 could help? the back of FW rubbing?... i'm baffled...

-Richard

 

[ArtemisI6]

Not sure about the starter failure.
With regards to the chatter, did you replace the pilot bushing?
Was the throwout bearing replace and is the input bearing retainer in good shape with no burrs etc so that the clutch engages smoothly?

Also was the transmission bellhousing made up or bolted all the way tightly to the engine block. If something is loose there, you can have an alignment issue with the transmission / clutch as well as the starter.
I mhave heard of some folks checking to see if the bellhousing is centered with respect to the crank. I have never done that, but some cars have adjustable dowell pins to provide better alignment.
Doug

I didn't replace the pilot bushing, but that was because I put the alignment tool into it and it was nice and tight with zero play. It also looked to be in good shape. I did replace the throwout bearing and input bearing retainer. I'm sure it's the pressure plate that's the issue as I found it with one of its retaining bolts snapped off, so I'm guessing it got slightly warped. My girlfriend (it's her car) hasn't had the money to replace it and since we figured out that we could drive it while avoiding clutch chatter, we haven't been extremely motivated in fixing it - however she's considering replacing it now that I have the transmission down again just to solve that issue once and for all.

Yes, the bellhousing was bolted very tightly. I once had my transmission come loose in my truck, and one of the symptoms of that is the clutch stops engaging fully. First you'll go to shift/put it into gear and it'll be tough but it'll go in, then it'll start to grind and pop in, then it won't go into gear at all. I matched rpm's without the clutch so I could still get it home. This didn't happen in this car at all. I was able to fully disengage the clutch every time.

First thing I thought this might've been was the starter coming a bit loose because that happened on my truck too, but nope, those bolts were tight as heck too.

This is why I'm frustrated... my last guess was the flywheel was coming loose - and it's not. The last thing I can say is the starter is to blame, but I don't know how I can check to make sure of that. I don't know what to tell my girlfriend because a new flywheel and starter are gonna hurt her wallet and if I don't solve the problem and it ruins those too, it'll be terrible.

 

[Frankenstang]

Sometimes ring gear/flywheel teeth just wear out...happens over time.
EDIT: Doubt you did signifcant additional damage in a short time to what was already there on the flywheel/ring gear teeth.
The bendix on the starter is definitely softer and designed to take more wear than the hardened teeth of the ring gear/flywheel, but they still chip and wear eventually to the point where you hit a particularly worn spot and it just won't spin the flywheel. Likely that you just need to replace the ring gear, but doubt you need to change the starter unless those bendix teeth are really hammered. Ring gear teeth will wear down eventually again...but should not be for a very long time.

I have experienced some mild chatter in breaking in a disc to a newly surfaced flywheel with free travel not correctly adjusted, but that should go away shortly after break in and with free travel properly adjusted...usually you just have the bad smell similar to seating new brake pads.

If you suspect the pp could be warped or worn, probably just as well you put a clutch kit in it while you're pulling the flywheel for a new gear...might as well spring for a new pilot bushing while you're in there as well...understand none of this is likely a welcomed expense
Good luck!

 

[ArtemisI6]

Sometimes ring gear/flywheel teeth just wear out...happens over time.
EDIT: Doubt you did signifcant additional damage in a short time to what was already there on the flywheel/ring gear teeth.
The bendix on the starter is definitely softer and designed to take more wear than the hardened teeth of the ring gear/flywheel, but they still chip and wear eventually to the point where you hit a particularly worn spot and it just won't spin the flywheel. Likely that you just need to replace the ring gear, but doubt you need to change the starter unless those bendix teeth are really hammered. Ring gear teeth will wear down eventually again...but should not be for a very long time.

The car has only gotten maybe 700 miles put on it since I pulled the transmission six months ago. When I pulled the flywheel and had it machined the teeth weren't pristine - they were used, obviously... but there weren't any even partially missing.

Now about 120* of the flywheel has teeth that are halfway ground off... the starter's bendix looks the same way. One half of each tooth is ground clean off. Since I never heard even a hint of any grinding or skipping or anything until yesterday, I have no choice but to assume that it all happened in one day.

Has anyone ever replaced a ring gear? It looks like it'd be a real pain. Failing that, where can I get a new flywheel? I can't seem to find a listing for one anywhere... only ring gears.

 

[Frankenstang]

The car has only gotten maybe 700 miles put on it since I pulled the transmission six months ago. When I pulled the flywheel and had it machined the teeth weren't pristine - they were used, obviously... but there weren't any even partially missing.

Instead of scratching my chin, I'm scratching my head. Seems odd the teeth would show that much damage that quickly, but it is what it is. Stubby just described to someone the other day how to change a ring gear (about halfway down the page):
http://fordsix.com/forum/viewtopic.php? ... ht=#437131

Or you could search the forum for "ring gear" and I'll bet there's more there. IIRC I read up here where someone put the flywheel in the oven and the ring gear in the freezer to slip it on...the specifics would be in an older thread.

Flywheel to crank shaft torque only calls for 23-33 ft lb for 6cyl (bent8 is 40-50ft lb for reference). I wonder if this could have anything to do with over torquing the flywheel. The other couple things I would want to check if I were in your shoes would be; could the flywheel be warped (given your chattering)?
EDIT: Just re-read where you found a broken pp bolt, those call for 23-28lb (specs are from fomoco manual). I'd replace all those and step up to grade 8 bolts & lock washers if they aren't already. Over torquing can cause stretch in the bolt and cause them to break...especially those smaller ones.
Is the ring gear seated properly and true?, I'd also want to check the nose cone bushing on that starter and make sure the end of that shaft is not dancing around...you can bench test it with jumpers, make sure you've got it held down.

I think there are new flywheels out there available, but can't remember who had them. There is a bronco parts dealer referenced up here often that is also a source, but can't remember the name...sorry, my brain is failing me. I do know for a fact some folks have had success finding a used flywheel here: http://car-part.com/
Good luck!

 

[CoupeBoy]

Or you could search the forum for "ring gear" and I'll bet there's more there. IIRC I read up here where someone put the flywheel in the oven and the ring gear in the freezer to slip it on...the specifics would be in an older thread.

This is backward, flywheel into the freezer and ring gear into the oven.

The broncograveyard is the most reported URL for finding replacement flywheels, but I can't find one today.. I'm sure a link is posted somewhere on this forum.

-ron

 

[ArtemisI6]

The car has only gotten maybe 700 miles put on it since I pulled the transmission six months ago. When I pulled the flywheel and had it machined the teeth weren't pristine - they were used, obviously... but there weren't any even partially missing.

Instead of scratching my chin, I'm scratching my head. Seems odd the teeth would show that much damage that quickly, but it is what it is. Stubby just described to someone the other day how to change a ring gear (about halfway down the page):
http://fordsix.com/forum/viewtopic.php? ... ht=#437131

Or you could search the forum for "ring gear" and I'll bet there's more there. IIRC I read up here where someone put the flywheel in the oven and the ring gear in the freezer to slip it on...the specifics would be in an older thread.

Flywheel to crank shaft torque only calls for 23-33 ft lb for 6cyl (bent8 is 40-50ft lb for reference). I wonder if this could have anything to do with over torquing the flywheel. The other couple things I would want to check if I were in your shoes would be; could the flywheel be warped (given your chattering)?
EDIT: Just re-read where you found a broken pp bolt, those call for 23-28lb (specs are from fomoco manual). I'd replace all those and step up to grade 8 bolts & lock washers if they aren't already. Over torquing can cause stretch in the bolt and cause them to break...especially those smaller ones.
Is the ring gear seated properly and true?, I'd also want to check the nose cone bushing on that starter and make sure the end of that shaft is not dancing around...you can bench test it with jumpers, make sure you've got it held down.

I think there are new flywheels out there available, but can't remember who had them. There is a bronco parts dealer referenced up here often that is also a source, but can't remember the name...sorry, my brain is failing me. I do know for a fact some folks have had success finding a used flywheel here: http://car-part.com/
Good luck!

I can't explain it to you, but that's how it is. The car hasn't gone a week without something breaking so it hasn't gotten much mileage on it since my girlfriend originally bought the car. The only thing I can guess is that after it started grinding (and that sound got ugly REALLY fast) I had to make a bunch of other stops before getting it home, so I had to continue just grinding the bendix against the ring gear to get the thing home.

I didn't realize the torque was so low on the flywheel bolts. My truck (300ci)'s Chiltons said 70-80ftlbs when I did that one if I remember correctly, so I just torqued them close to that assuming it's be good enough.

I'm going to check out all the things you guys suggested. Thanks for the advice.

I think I'm going to try replacing the ring gear instead of a new flywheel. I just hope you guys aren't making it sound too easy. I'm also going to replace the starter with one from my job while I'm at it because it's some Autozone piece of crap. Thanks a lot guys, I really appreciate it!

Lastly, my girlfriend is intent on buying a new clutch while everything is out. Can anyone recommend a good diaphragm clutch? We want the 3-finger clutch out of there.

 

[aribert]

Just an idle thought, is the motor plate (block plate) present between the motor and the bellhousing? If not, the starter motor is not properly restrainded relative to the flywheel ring gear - this could cause all sorts of grinding and wear.


Although I see that you are looking at just buying a ring gear, the URL to
Jeff's Bronco Graveyard is: http://broncograveyard.com/

Just a small word of caution: I am using a Bronco flywheel in my 3.03 upgrade and as I understand it the Bronco flywheel is slightly different in size and the ring gear has 4 additional teeth on it (seems to mesh OK with the Falcon/Mustang starter)

 

[ArtemisI6]

Just an idle thought, is the motor plate (block plate) present between the motor and the bellhousing? If not, the starter motor is not properly restrainded relative to the flywheel ring gear - this could cause all sorts of grinding and wear.

Yeah, the block plate's there. I also checked TBG and couldn't find a 200ci flywheel listing on there at all.

 

[Frankenstang]

Flywheel to crank shaft torque only calls for 23-33 ft lb for 6cyl (bent8 is 40-50ft lb for reference). I wonder if this could have anything to do with over torquing the flywheel.

ArtemisI6, Sorry man! I totally screwed up here ...your torque was about right, book actually says 'Flywheel to Crankshaft 75-85 ft lbs all engines'....I was giving you bellhousing torque...my bad! Those numbers bothered me the more I thought about them, that and I need to stop looking this kinda stuff up in the wee hours :roll:...pp numbers are correct, I triple checked

 

[ArtemisI6]

Ooh! okay, good, thanks! I'm glad to know I didn't overtorque them and possibly warp the flywheel. I don't want this to have any chance at being my fault! Thanks Frankenstang.


Can anyone recommend a decent diaphragm clutch for the car? We don't need anything fancy. She's not intending any performance mods with this car - we just need something affordable, reliable, and affordable in the form of a diaphragm clutch. She wants to be rid of the three-finger job. Did I mention affordable? Thanks guys!

 

[Frankenstang]

AFAIK any '78-'82 clutch kit for the ford 3.3l/200ci should work and will be diaphragm. Dowside is the kit will come with a TO for a cable fork that you can't use, but IIRC yours is not that old. There are a couple inexpensive options on fleabay:
Ford Mercury 3.3L Mustang 1978-82 clutch kit #10011
78 79 Ford Fairmont 3.3 3.3L OEM Replacement Clutch Kit
78-82 MUSTANG(II) 3.3L 6CL STAGE 1 CLUTCH KIT

The first one has the look of a semi-performance style (at least the disc does), and that stage II one is interesting. Basically any 78-82 pp for a 200ci should be diaphragm style and you might be able to get the disc and pp cheaper in a kit, but again the TO won't help you. You might also check RockAuto. They run some good specials/closeouts now and the. Selecting by mode, '78 Fairmont seems to be popular. I picked up a Ram set cheap for an '80 mustang 3.3l when MU was closing them out and it works great.
Good luck!

 

['68falconohio]

One day I got in my car to go to work and the starter wouldn't engage, it just ground on the flywheel extremely bad. I bumped the starter 3-4 times to get it to turn over enough to start, swung through NAPA and picked up a starter, kept it running, and drove to work where I could change it. This was the first time that the starter had never fully engaged/ground and when I pulled it out, the teeth were layed over really bad on the front half of the gear. It looked like it had been grinding for weeks but it hadn't. The flywheel was chewed up a little bit but not having the time/money to pull the trans and whole get-up left me to relying on the new starter gear to mesh. It did.

I'm not an expert, but I only had to get my car running one time with it grinding and it did some damage to both flywheel and starter bendix. If you had to do this several times, I'd guess it would cause substantial damage. My starter was tight when I went to replace it and I put the new one in and have had no problems since. Like I said, the starter NEVER ground on the flywheel before then, but once it did, it was angry and ready to cause pain. My car is an automatic and I'm not sure if they take the same starters or the starters were designed with the same components. Just thought I'd tell you what happened to me.

 

[tony1963]

I had a Volvo once that did something similar. It turned out to be a bad thrust bearing on the crankshaft that was letting the crank and everything attached to it move forward and aft.