Stuck starter motor

M

Mad Mac

Senior Member
The usually reliable starter motor in my '29 RPU has started sticking lately. It sticks in maybe one out of 10 starts and after rocking in top gear it un-sticks quite easily. Can anyone explain why it is doing this and what I should do to fix it? The search function didn't supply the answer.
 
Mad Mac said:
The usually reliable starter motor in my '29 RPU has started sticking lately. It sticks in maybe one out of 10 starts and after rocking in top gear it un-sticks quite easily. Can anyone explain why it is doing this and what I should do to fix it? The search function didn't supply the answer.
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The first thing I would do is pull the starter and see if the bendix is good, then crank the motor over and see if the ring gear is pulling forward off the flywheel.
 
Spray it good with brake cleaner. No oil should be on it. Make sure you press firm when starting. Partial start will lock it up.
 
Remove the starter and inspect the starter ring gear on the flywheel. It should be seated flush up against the stop on the flywheel. Henry should have had the stop on the opposite side as each time the starter engages it wants to pull the ring away from the stop. Some repos do not sit tight on the flywheel and will eventually walk away and leave a space.

You can rotate the engine a few degrees at a time and drive it back into place with a hammer and a punch.

Mine got so bad I finally had to remove the flywheel and have a new ring installed. I had the shop drill and tap in several places and secure it with set screws.

Tom Endy
 
I would check the Bendix as suggested, I had a lockup at a show and no amount of rocking freed it up. I had the car towed and had to take the starter apart to get it out. In my case the pinion gear on the Bendix was badly worn and I wasn't aware of it before. Save yourself some aggravation and solve the problem now.
 
Tom Endy said:
Remove the starter and inspect the starter ring gear on the flywheel. It should be seated flush up against the stop on the flywheel. Henry should have had the stop on the opposite side as each time the starter engages it wants to pull the ring away from the stop. Some repos do not sit tight on the flywheel and will eventually walk away and leave a space.

You can rotate the engine a few degrees at a time and drive it back into place with a hammer and a punch.

Mine got so bad I finally had to remove the flywheel and have a new ring installed. I had the shop drill and tap in several places and secure it with set screws.

Tom Endy
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I had the same problem, drove mine back on and drilled and taped it trough the starter hole. No more problems with it.
 
Could be a bad spot in the ring gear. If it is, starter may "stick" every time the engine stops on that spot on the ring gear.
 
Coating the FLYWHEEL teeth with Wheel Bearing grease helps.
I learned that MANY years ago, workin' on Jaguars. Up to 1964, they had a very similar Inertia type drive. "Sometimes" when they would jist go "WHIRRR" & wouldn't engage, I'd jist RAP the starter, with a BIG HAMMER!--Never tried that, on a Model A????
Better get out of here, Folks might git tired of seeing my NAME! BUT, whut's a Guy do, whin sumbody asks for HELP? & a little "humor" to start their day??
Bill British?
 
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Thanks everyone, I will do what you suggest. Beaufort (post #4) says no oil should be on it and Bill (post #9) says put some grease on the ring gear. Is that a contradiction or are they referring to different things?
 
Mad Mac said:
Thanks everyone, I will do what you suggest. Beaufort (post #4) says no oil should be on it and Bill (post #9) says put some grease on the ring gear. Is that a contradiction or are they referring to different things?
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NO oil or lubricant on the Bendix Spiral, just clean & dry.
Bill W.
 
Mad Mac said:
Thanks everyone, I will do what you suggest. Beaufort (post #4) says no oil should be on it and Bill (post #9) says put some grease on the ring gear. Is that a contradiction or are they referring to different things?
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I give the helix on the Bendix drive a coat of light oil, such as ATF. I grease the flywheel ring gear, but don't lay it on too thick or it will sling onto the helix and gum it up. It that happens, then remove the starter and clean it off.

I don't drive my Model A when the temps drop below 40*, so a coat of light oil on the helix won't bother the engagement. It one was to use heavy oil, then you'd have to click the starter several times to make the drive move up the helix. Or, you can just use the hand crank. :)
 
I have taken it off now - see the attached 3 pics. There is a very small amount of grease on the spindle (the spindle is that small cog, right?) and plenty on the helix but there does not appear to be any grease on the ring gear. Can you see anything in the photos that indicate the cause of it sticking? The shaft does not appear bent when I rotate it.
 

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And a related question: When I took the starter-motor off, I decided to take its front cover off to look inside (it was a dumb thing to do, because I don't know enough about electrics to identify any problems anyway). And when I tried to re-assemble it I got frustrated trying to spread the spring-loaded brushes apart far enough to slip them back onto the bronze thing that rotates inside them. I am sure there must be an easy way of doing this? Sorry, I don't know the correct name for the bronze thing that rotates.
 
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Mad Mac said:
And a related question: When I took the starter-motor off, I decided to take its front cover off to look inside (it was a dumb thing to do, because I don't know enough about electrics to identify any problems anyway). And when I tried to re-assemble it I got frustrated trying to spread the spring-loaded brushes apart far enough to slip them back onto the bronze thing that rotates inside them. I am sure there must be an easy way of doing this? Sorry, I don't know the correct name for the bronze thing that rotates.
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The bronze area you are referring to is the "Commutator" located on the "Armature" which is the part the electronic pixies run through to turn the Bendix.

Now, there are tricks to getting the brushes spread wide enough to slip it back onto the commutator which usually depend on small pieces of wire and holding your tongue just right.

The way I always did it was to slide the armature a bit out of the end you took the plate off of and use cut coat hanger pieces to hold the brushes back enough to get the cap back on the armature shaft, then remove the wires and slide the whole thing back together.

You can make little right angle hooks, slide the brush back in the holder, slip the hook into the copper wire on the back of the brush and bend it over the edge of the end cap to hold it. Do not slide it through the spring as that may not hold the brush in the guide.
 
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I usually pull the 4 brushes back far enough to **** them in the holders, so they aren't actually in place. Then I can slip the end plate on and bolt it in place. Then I use a hook to left each spring and slip the brush into the holder. Be sure the springs are centered on the brushes, or the brushes will wear at a slant.

Clean the grease off the helix, and you should be good to go. I like a bit of thin oil on the helix to make sure it doesn't rust.
 
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