The Stovebolt Site Forums The Shop Area The Electrical Bay Question: armature play in a 6volt starter for 1954 235 for 3100

Bought a 54 with Low miles in a rebuilt 235. Stock motor.

Starter spins well and is strong. However, it grinds. So it is either the ring gear or starter motor's drive gear or ?.

Dropped the starter. Drive gear is a bit chewed
Up.

Stand starter on end and armature slides into the housing about an 1/8 of an inch. Stand it on the nose and the armature slides abt 1/8 of an inch to the front of the unit.

I have changed a few starters but am not by any means an expert. Should the armature do this? I don't think so but I am hoping for some advice (thanks in advance)

The intermittent gring may be tied to this?!?

Armature in photo:
[img]https://goo.gl/photos/tn79YTDDVPHMDJmz8[/img]

Amarture out photo:

[img]https://goo.gl/photos/7vZCtpR4hgsn49FH8[/img]

Are you running 6 or 12 volts? It sounds like you've got a mismatch between the starter pinion gear and the flywheel teeth. A 6V flywheel has 139 teeth and a 12V (55-up) flywheel has 168. Both starters have 9 teeth but the gear pitch and diameter is different. A 12V starter has about a 1/2" diameter shaft, and a 6V starter has a shaft about 5/8" in diameter. There is a fiber thrust washer under the rear cover of most starters that is supposed to control the end play. Yours might be worn out.
Jerry

The motor is a 54 and I am assuming it is a 6volt flywheel. I will check tomorrow. The starter does grab and spins the engine 2 out of every 3 attempts to start. On the 3rd attempt it grinds . I have to endure usually two additional grinding stomps before the starter grabs.

I assumed it was a bad gear ring on the flywheel but will first double check to make sure the flywheel Is a 6 volt variety

You can tell whether an early Chevrolet or GMC starter is 6 volt or 139 ring gear teeth because the starter drive pulls out straight. The armature has straight splines. The 12 volt or 168 tooth ring gear starters have helical splines on the armature and will twist when pulled out.
Also the "exposed end of the starter shaft on the
12V starter will be .470" while the 6V starter has a shaft diameter of closer to 5/8".
ALSO: If the return spring on the foot start linkage is missing/broken/wrong one/weak, that's your problem.

All I will say is that I had a bad drive for a time. The ends of the drive gear were quite chewed up. It started to chew up my ring gear pretty quickly so I definitely would not use it that way.

If the starter pinion and the ring gear are compatible, I'd suggest changing the starter drive out for a new one, and maybe flipping the ring gear over on the flywheel to get a fresh set of teeth exposed to the pinion gear. It's not terribly difficult to do if you have access to a torch to expand the ring gear once you tap it off the flywheel with a hammer and a soft punch.
Jerry

Starter

[img]https://goo.gl/photos/7vZCtpR4hgsn49FH8[/img]

Starter drive gear

[img]https://goo.gl/photos/f4cbENbrawfHhbt48[/img]

I am confident it is a 6 volt starter, the starter drive gear is in good shape (I think),

I have no reason to believe the rebuilder changed the flywheel. It was rebuilt by a hot rod shop in Wisconsin. They did the 12volt conversion - this gives me confidence that it is a 6 volt flywheel ( but will double check). I do greatly appreciate the input - this is what makes this site awesome!!!

I do not want to drop the tranny (sm420) and I am hoping it was the starter drive gear. I do not think it is that.

Then I noticed the amateur moves freely within the starter motor housing; and when I say move freely I mean forward and back not rotational.

My question is: should the amateur move back-n-forth in the starter motor housing by an 1/8 inch?

Look at the tip of starter motor in these two pics and you can see the travel:
[img]https://goo.gl/photos/Gp4gVE7HdP5Mb5Yj9[/img]

And

[img]https://goo.gl/photos/Nzca45B4gCFYMLey5[/img]

To me that does not seem normal -- maybe it is wishful thinking in hopes of not having to drop the tranny

Jerry,
thanks for advice. Dropped plenty of manuels and automatics granny's as a young man..... never one with tourque tub! Should be fun! Partly one of the reason I bought that old truck !

I don't know if 1/8 is normal, so my observations and theories are just that.

1. If the gears are all good and the you see the drive gear and foot pedal linkage is operating as designed and the return spring, I already mentioned, is good and the "grinding" is coming from the gear mesh/non mesh and not growling from a bad starter motor........then it would have to be the 1/8.
2. 1/8 does not seem to be enough if ALL of the above are correct.
3. If 1/8 is not normal for that starter it would be easy to see where the 1/8 is coming from. I.E. what is missing on one end or the other regarding bushings, spacers, "stops", bearings. Starters are just motors. Easy to take apart and check the end play components, brushes, commutator and etc.... if you are at all mechanically inclined. Two long bolts. Would you want to take off the ring gear if you haven't assured it's not the starter? No. It seems you are saying that the gears are not bad?
4. There is a member here kennethw who knows the answer. Has a rebuild business for these starters and generators and such.
PM or [email protected]
5. I mention the foot stomp return spring because another member had grinding/intermittent mesh and it turn out to be a missing return spring. Check Loose linkage or any factor that would keep the drive gear from slamming home every time. Put it back on and check with power off.
6. You don't know if the shaft moves back and forth when starter is engaged on truck. 1/8 would seem to still engage. But agree, it would bother me too.
7. If the growling noise is caused by partial engagement, that can even be the foot switch, electrical intermittency somewhere or the other components I mentioned and not the 1/8 or the gears. You have to observe the action 20 times with someone stomping (power off). Stomp and hold, observe engagement depth somehow, over and over.

The pic with the armature shaft flush with the front of the starter housing is the normal position. Drop the rear plate off the starter and check out the fiber thrust washer- - - -it's probably worn or missing.
Jerry