Starter Lockup Problem

[56servi]

Yesterday when I went to start my 31 S/W the starter motor locked up. I tried rocking the car in 1st gear but no help. I got the starter out today. Had to bang on the starter with rubber mallet to get it to move. The end bolt on the spring housing (?) is loose but in place by the tab washer.
The spring is not centered around the shaft as seen in the pictures.

Do any of the parts look damaged & need to be replaced or just tighten the bolt & put it back in. What causes the lockup? Could it be a week battery? Yesterday when I tried to start the car it didn't start on the 1st try. When I tried again the engine didn't turn over. I thought the batter was low so I charged it. Could the lockup be due to a low battery & not engaging the bendix with enough force?

[700rpm]

It looks like the shaft is bent.

[56servi]

I think your right. Time to take it apart

[Marshall V. Daut]

Once you have removed the Bendix drive and spring, test the shaft's trueness by using jumper cables from the 6volt battery to the starter. Doesn't matter which way you connect them to the starter as long as one cable end is attached to the starter flange and the cable end is touched against the brass terminal. Hold the starter firmly because it will want to move. The shaft will spin at a high rate of speed, but should not be blurry. If you see a blur, then the shaft is bent. If the shaft spins cleanly without any blurring, it's probably o.k. If bent, however, either straighten it or replace the armature. Do not re-install the starter with a bent shaft. It WILL lock up again.
Marshall

[Bob C]

You will have better luck rocking the car in 3rd gear.

Bob

[56servi]

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The shaft is out of round by .100 at the end. Measured with drive assy removed.
What are Recommendations:
A> Buy a used starter off ebay
B> Buy a new armature & repair old starter

[Marshall V. Daut]

You have nothing to lose by trying to straighten the shaft in a vise. Place the shaft between the vise's jaws just below where the bend is located. Then use your body weight to pull/push the armature in the opposite direction of the bend in the shaft. Remove and check for trueness after each pull/push. This could solve your problem for no cash outlay. At worst, you will need to buy a new/rebuilt armature if you can't straighten the shaft yourself. No need to buy a completely rebuilt starter if yours worked well before you experienced lockup. The bent shaft is a result of too many times starting the engine without first retarding the spark. The resulting kick-back by the flywheel is what bends the shaft. Be sure the initial timing is not too far advanced and that you move the spark lever up to its high point EVERY time you start the engine.
Marshall

[Brentwood Bob]

also noticed that the face of the starter housing is painted.
I clean to bare metal on both contact surfaces.
also remember the longer attachment bolt goes next to the steering column on the reinstall.
Bob

[Tom Wesenberg]

Use a couple V blocks and a press to straighten the shaft. Just rotate the armature until the high spot is up, then press down on that spot. If you don't have a press and V blocks you could even use wood blocks and a piece of hardwood and a hammer to tap the shaft.

As Bob said, use 3rd gear and rock the car forward to spin the Bendix out of engagement. Yes, a weak battery can leave the Bendix engaged. A bad ring gear or bent starter shaft can make the Bendix jam.

You starter drive looks excellent, but the spring looks like the style that requires the two shims. 15968 is Bratton's part number. These help to fill the gap at the end coil so the spring doesn't pull the bolts at a bad angle. If the end coil on each end of the spring doesn't come in with a smaller inside diameter than the rest of the spring coils, then you need these shims. Your spring appears to have all coils the same inside diameter. This is also probably why the bolt feels loose. You might want to order new locking tab washers when you order the shims.

Part number for shims 15968 .........lock washers 16000
Bratton's 800-255-1929

[56servi]

I can take it to work. We have V blocks & a hand press. Should I remove the armature to straighten the shaft or leave it in the starter. I will be doing this tomorrow

Thanks for the help

[Tom Wesenberg]

Originally Posted by 56servi

I can take it to work. We have V blocks & a hand press. Should I remove the armature to straighten the shaft or leave it in the starter. I will be doing this tomorrow

Thanks for the help

Actually you should be able to leave it assembled except to remove the Bendix. You'll be pressing down right next to the drive endplate.

[Tom Wesenberg]

Here's a tool I made several years ago to straighten starter shafts. It's easy to make and works well. Don't ask for dimensions, because it's just some scrap metal I had laying around, and no dimension is critical. You just watch the flat washer on the bottom as you rotate the shaft. When the washer is closest to the channel iron, then you stop rotating and tighten the nut to pull the shaft down. After a few you get the feel for how much to tighten to move the shaft.

[Fullraceflathead]

Originally Posted by Tom Wesenberg

Here's a tool I made several years ago to straighten starter shafts. It's easy to make and works well. Don't ask for dimensions, because it's just some scrap metal I had laying around, and no dimension is critical. You just watch the flat washer on the bottom as you rotate the shaft. When the washer is closest to the channel iron, then you stop rotating and tighten the nut to pull the shaft down. After a few you get the feel for how much to tighten to move the shaft.

I like that tool Tom!
Looks like another Model A specific tool I'll have to make.

[Jacksonlll]

In third gear, and always rock it rearward.

[Jacksonlll]

Here is a short video I did on the subject.
https://www.youtube.com/watch?v=PD4A...rIa0r_fFQcz4R0

[Tom Wesenberg]

Originally Posted by Jacksonlll

In third gear, and always rock it rearward.

Third gear FORWARD is what will spin the Bendix rearward on the helix.

Either forward or rearward might dislodge the drive from the stuck position, but it's the forward motion that will spin it rearward and out of engagement with the ring gear.

[glenn in camino]

Also, try one of the new modern Bendix.

[56servi]

After taking the armature out I decided to get a new one. The commutator was severely worn with a big step where the brushes run. I also ordered the springs that Tom mentioned and new bolts & washers, and brushes.

Thanks for all the help

[a guy]

For what it's worth. Also had a starter that would not disengage . I checked the starter switch and found the copper plate to be warped. Pulls a lot of current. Once out of shape will not go back to proper position. Replaced switch and all is well. Plunger that starter rod screws into was also worn. Worthy of inspection.

[56servi]

I finally got the starter back in & working. The 1st armature I got off ebay had a bent shaft. The endplate would not slide on the shaft all the way. Ordered from another vendor & it was OK. I replaced the 2 brushed that bolt in & added the spring clips that Tom suggested. I used small zip ties to hold the brushes back when installing the armature. I put a stud in the top mounting hole of the bell housing to hold the starter while starting the other 2 bolts. Starters get heavy when leaning over the fender trying to hold them up.

Thanks again for all the help