The Stovebolt Site Forums The Shop Area General Truck Talk teeth broke on starter drive

My '49 Chev panel has a 1955++, 270 ci GMC engine. Could not start yesterday. Starter removed, teeth broken on starter drive. Truck converted to 12V. Key switch start. Solenoid says 12V.
Part number on starter is: 1108365 OC 2 6 Delco-Remy USA.

What may have caused the teeth to break? (Starter drive teeth to flywheel
teeth mis-matched because of engine swap?)
What's the fix?
Where is a good place to buy the parts?
Rebuild starter and starter drive?

Any guidance appreciated.
Jerry Bubolz
Gilbert, AZ.

I would count the number of teeth on the flywheel. Then you will know what you have without guessing.

I think that GMC and Chevrolet flywheels have the same number of teeth, and, maybe the same diameters.

Chevrolet:
6v 139 teeth
12 168 teeth

Just talked with an "old" Chev. line mechanic. He says broken teeth on starter drives were a common problem back in the day.

Is the tooth count more important than just looking to see how the starter drive teeth match the flywheel?

Jerry

I would be first concerned that you have a starter drive that is compatible with your flywheel. As Tim points out one is 139 teeth and the other is 168. They both use a different starter drive.

I gather that you've been driving this truck for a while and it has been ok. Fortunately the drive (Bendix) is available separately once you determine the flywheel tooth count.

yaneed to quit chewing on starter drives. no wonder you broke yer teeth.

actually, the problem isn't quite that uncommon. bad heat treat made many of them too brittle and they would strip off the teeth clear around. g.m. did the fix decades ago. it's not common as much these days since over the years most starters have been replaced at least once, and rebuilders don't save the old bendix during rebuild. better take a hard look all around the flywheel.

oh, as I remember, the problem manifested itself more with out of tune engines, especially timing.

I acquired the panel in August and driven it several times per week. I'll admit, the starter did not sound normal.... whatever that is.

I will have to count the teeth on the flywheel. No telling if the flywheel came with the engine swap or ?? Engine is 1955 GMC 270 c.i. or newer. (?)
Panel truck is '49/'50, 1/2 ton.

Took the starter and solenoid to Gen-Star Electric, Inc. Glendale, AZ.
$60.00 to rebuild with new bushings, brushes and starter drive.
They have been in business for 50 years. Owner is the grand son.
If you ever want to see an old time mechanics shop, stop by Gen-Star.
Will advise Gen-Star the tooth count tomorrow morn.

Thanks a heap for the advice....
Jerry

Something that might be worth notating; The '55 2nd GMC did carry over the 6 volt system on 6 cylinder trucks. I'm not 100% sure how far after that it went, or if GMC had the different tooth count like Chevrolet did.

Bill is correct: the 6v electrical system (positive ground, I guess) was standard in late 1955 GMC Blue Chip trucks that had a 6-cylinder engine.

In 1956, all GMC trucks had standard-equipment 12v negative ground electrical systems.

I did a flywheel tooth count this morning. 139 teeth.
Advised the starter rebuild guy.
Ring gear looks pretty good.

Jerry

Put a 6 volt starter in and you'll be good to go, just don't crank on it to long with 12 volts.

Don:
A 6V starter could be the answer. Thanks for that solution.
Jerry

Got the starter back from the re-build shop. $61.00
New bushings, new brushes, new starter drive. Bead
blasted and painted. Looks new!

Installed and took the truck for a test drive. Now it
starts quickly and the starter motor hums a lot quieter.
139 tooth flywheel and starter drive to match on a 12V
starter and solenoid. Key start.

Thanks for all the help from you "bolters".
Jerry