starter/Bendix/Flywheel?

[Willynch]

1930 Tudor

Would not start. Sounded like starter motor was spinning rapidly without any engagement between starter/Bendix and flywheel.

Thought Bendix was bad so replaced.

Same issue.

Seems like the Bendix drive assembly is not engaging the flywheel.

Is there a way I can see the flywheel and Bendix when I am trying to start?

Could flywheel/Bendix be out of alignment? Starter is seated appropriately.

Not sure what to try next.

Would appreciate thoughts/insight.

Thanks

[Tom Wesenberg]

Did this just start, or did you just get this car?

Hopefully no grease is on the helix of the Bendix drive. I use a light coat of ATF to let it slide, and to keep it from rusting.

The long bolt and key MUST be installed on the rear end of the armature shaft. The short bolt MUST be on the forward end of the Bendix drive, near the bushing and mounting plate. The lock washers must be folded tight to the flat on the 2 bolts.

[Big hammer]

I was testing a starter motor yesterday and it would not spin. Then I placed the cables on correctly positive + red to ground, and negative - black to the motor button and it spun !

[frank55a]

Many Model Aers do not understand this, but when the engine is stopped about 90% of the time the engine will come to rest at 1 or 2 places. Therefore when starting a small amount of wear is incurred at either of those spots when the bendix is engaged, over time this wear will compound and the ring gear teeth will wear out in those spots. About an inch of very heavy wear at the main point of contact and about another inch on either side of those spots. The rest of the ring gear will most likely have very little wear. Try putting the A in 3rd gear and moving the "A" a bout a foot so the motor/flywheel will rotate away from that spot, then try starting the A again normally. If the starter engages then your ring gear is worn out and needs replacement. If you can live with it just remember to push the car slightly prior to starting to move off those spots. Otherwise you have major work.

[Willynch]

I will try that.

I did use the hand crank thinking that would move the ring gear relative to the Bendix pinion gear. I guess my thinking is wrong??

[Tom Wesenberg]

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The hand crank should have moved the ring gear to a new spot.

Hopefully you have the correct drive, which has a left hand thread on the helix.
Some drives look correct, but have a right hand thread on the helix.
The same thing goes for the drive spring.

[Jacksonlll]

My guess is heavy grease on the shaft.

[Terry, NJ]

You might have broken the Bendix spring, Always carry a spare. There's no warning, it just starts whirring and won't engage. Just pull the starter and you'll see it (if that's the problem)
Terry

[RawhideKid]

I am sitting here wondering why all the speculation when hot or cold, mine starts on a quarter turn of the crank with the hand crank.

Even if the starter dies, you are always able to make it home to remove it!!

[Synchro909]

It should be easy enough for you to see which way the tapered edges of the teeth on the ring gear are facing. On the Model A, they should face rearwards which is the opposite way to most cars and opposite to just about every modern car.
You don't say anything about the history of the car or whether there has been work done in the flywheel area recently. On my most recent Model A, the ring gear had been fitted in a modern workshop and they got it backwards. It all worked fine - for a while just as yours may have. I think it is worth having a look to verify. If it is wrong, the cure is easy, just take it off and reverse it. As mentioned in a post above, the engine usually stops in one of two positions. The ring gear wears at those places but rotating it 90 degrees on the flywheel would make it like new.
Please let us know what you find.

[Big hammer]

Originally Posted by Big hammer

I was testing a starter motor yesterday and it would not spin. Then I placed the cables on correctly positive + red to ground, and negative - black to the motor button and it spun !

Ok shouldn't a D.C. motor spin backwards when you reverse polarity ?
If the polarity was changed ? the bendix will not engage with the motor spinning backwards. That doesn't answer why my starter motor wouldn't spin with the polarity reversed, with it spinning with the correct polarity is all that matters.

[Tom Wesenberg]

The Model A starter has the armature and field windings wired in series, so if you reverse the polarity of one, you also reverse the polarity of the other, and the starter armature will still spin in the same direction.

A motor with a permanent magnet for the field will reverse direction when you reverse the battery connections because the field polarity can't change.

[Big hammer]

Originally Posted by Tom Wesenberg

The Model A starter has the armature and field windings wired in series, so if you reverse the polarity of one, you also reverse the polarity of the other, and the starter armature will still spin in the same direction.

A motor with a permanent magnet for the field will reverse direction when you reverse the battery connections because the field polarity can't change.

Thanks Tom!

[BILL WILLIAMSON]

In a PINCH & starter goes WHIRRR, bang on it with a BIG HAMMER & it'll engage!!!
Bill Crude