Starter jammed in flywheel.

[Joeyv]

I have a recurring issue with my 1940 Mercury. On what used to be a rare occasion, the starter motor would get jammed in the flywheel. When that happens, pushing the starter button results in nothing happening, not even a sound. Lately the problem seems to happen more frequently, typically at an inconvenient location. I have been told I could free that jam by rocking the car back-and-forth, but I have never had success doing it that way. The only way I’ve been able to free it is to loosen the bolts of the starter and back it out. Sometimes it requires prying with a screwdriver to get the starter to separate from the flywheel. I’ve heard several opinions on what the cause of this problem is. I’ve been told it’s an issue with the starter, that it is not functioning as it should; it needs the brushes replaced, or the centering plate replaced. I had the centering plate replaced and it still jammed. I’ve also been told that cause of the problem due to the flywheel which will consistently stop at a couple of locations when the starter is used to start the engine. Those locations, overtime, wear those flywheel teeth down, and that’s where the start of motor jams.
Has anyone else experienced the same problem? If so, did you find the cause of the problem and a remedy that worked? Thanks

[Bob C]

The most likely cause is worn ring gear or bent starter shaft.

[Graeme / New Zealand]

Had that issue with my 48 but since starter has been overhauled it's been a lot better. Best way I found to free it was to put it in 2nd gear, go to the front of the car, grab the bumper in the middle and rock it towards you and back and it should free up first or second cycle.

GB

[deuce lover]

Could it be that the Bendix is getting jammed ?

[Ggmac]

Do you have the little bracket on the front of the starter that bolts to the oil pan ?

[chap52]

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The ring gear can also slip and become caddie-wampis (??) on the flywheel. Chock the wheels and put the car in neutral. If you remove the flywheel cover on the bottom and remove the spark plugs to make turning the engine with a large screw driver using the ring gear teeth and a little lever action.
The engine always stops at those two places and of course those are the ring gear teeth that the most wear. Do as Graeme suggested to possibly identify the issue. A starter is certainly easer to R&R than replacing that ring gear.
Keep us posted and if you have to go after that ring gear we can give you some tips on that.
Enjoy the adventure... Chap

[Joeyv]

Thank you all for the excellent suggestions. I will report back what we find as we explore the situation further.

[john greco]

Same thing happen to me , the fix was replace ring gear , it was jacked in one spot

[Joeyv]

I had the ring gear inspected and was told it looked as though all teeth were in good shape. The starter was rebuilt (again) and I put in a new battery. So far, no problems but since this was an intermittent problem, I am not ready to say the problem is resolved.
Thanks all for the recommendations. I’ll post in this thread if the “fix” does not continue to work, and the starter again locks up in the flywheel.

[petehoovie]

6 or 12 volt system?

[joe 1950]

i had that problem on my 50 cpe replaced the Bendix drive gear and it fixed it but just wanted to say that Ggmac is correct in stating about the bracket from the front of the starter to the oil pan bolt it’s very critical to have Ford and other manufacturers wouldn’t have put it there if it wasn’t needed hope this helps

[signsup]

Had similar problem on Model T. Recommended quick fix was to rock the T, but we never could get that to work, loosen screws holding starter in position and the bendix would spring back, tighten screws and be on our way.
Our problem was bent ring gear and when it jammed, rocking the car would not change the angle of the bendix teeth into the ring gear, so it never solved the problem until we removed ring gear, straightened out and replace.
It was suggested that running starter on 12v for a system designed for 6v was overpowering the thin ring gear metal.
Hope your problem is solved, but the rocking motion not providing a fix sounds like it may be the angle of attack, not worn teeth on either ring gear or bendix.
JMO

[19Fordy]

A friend of mine has been having that "jammed starter" problem for the last 6 months.
Finally removed the starter and found that one of the Bendix bolts had loosened and was stuck in the fly wheel teeth. He just happened to see it when he turned the flywheel tooth by tooth a little at a time. Otherwise you would miss it. Hard to believe but true. Working fine now.

[bmc]

Had this problem before as well. Found that the ring gear was working its way ever so slightly off the flywheel in spots where the starter bendix was making contact. 6v starter now using 12v causes one hell of a push/pull with the starter. Removed starter and inspection plate and the ring gear needs to be flush with the flywheel. I had to tap where they come together with a brass hammer in a couple spots while turning the engine over by hand. I would never have known about this until someone pointed it out.

[Joeyv]

All good information, thanks. My car is 6v. The bracket to the oil pan was also suspect as a contributing factor to the problem. We made sure it was tightened down properly to keep the Bendix properly aligned. That along with the other changes have, so far, resolved the problem.

[coup34]

Joeyy, try stopping engine with clutch, brake on, as engines tend to stop on compression ,might help untill fixed

[38 coupe]

I have experienced the jammed starter several times in vehicles with worth ring gears. The starter jams trying to move the engine forward. Putting the vehicle in third and rocking back and forth usually pops the starter free. If that doesn't work, put the vehicle in third and get someone to push the vehicle backwards then pop the clutch. You need the engine to rotate backwards, going the opposite direction of what caused the jam in the first place.

[Ken/Alabama]

Just make dang sure the ignition switch is OFF when trying to rock it.