Technical Starter Motor Question

[Luke W]

I have a 1969 Fiat 500L that I am reconditioning. The engine is out and so I figured I would put in a new bendix gear which seemed a little worn and bronze bushings to deal with the play in the starter motor. The starter was working well except it had intermittent spinning before I removed the engine.
I cleaned up the switch and bench tested the starter and it has stopped working altogether, I removed the switch and tried to start it directly from the terminal and still nothing. I am wondering if something internally could have got burned out. It seems like there really aren't a lot of parts to go wrong so I am stuck on what might have happened.
Any ideas or help would be greatly appreciated.
Thanks,
Luke

 

[the hobbler]

I have a 1969 Fiat 500L that I am reconditioning. The engine is out and so I figured I would put in a new bendix gear which seemed a little worn and bronze bushings to deal with the play in the starter motor. The starter was working well except it had intermittent spinning before I removed the engine.
I cleaned up the switch and bench tested the starter and it has stopped working altogether, I removed the switch and tried to start it directly from the terminal and still nothing. I am wondering if something internally could have got burned out. It seems like there really aren't a lot of parts to go wrong so I am stuck on what might have happened.
Any ideas or help would be greatly appreciated.
Thanks,
Luke

Check that (a) the brushes are touching the commutator and, (b) that the wires from the brushes are not shorting out on the body of the starter.

 

[Bounding Bambino]

Check that (a) the brushes are touching the commutator and, (b) that the wires from the brushes are not shorting out on the body of the starter.

Also to add for the op. the brushes are directional. The brush holders have slots in them for the brush wire to side in as the brush wears. Even though there are 2 slots, one is deeper then the other, and the brush will prematurely stop if the wire is on the "shorter" side. Something to keep in mind when assembling.

Had my new to me starter give out after only a few months. Turns out the brushes were in backwards, and the wire was stuck on the shorter slot.

With that said, its not easy to route the brush wire properly without touching the case, but it is possible. Also, you might need to "adjust" the brush housing so the brush slides thru without any resistance or catching up.

 

[the hobbler]

Also to add for the op. the brushes are directional. The brush holders have slots in them for the brush wire to side in as the brush wears. Even though there are 2 slots, one is deeper then the other, and the brush will prematurely stop if the wire is on the "shorter" side. Something to keep in mind when assembling.

Had my new to me starter give out after only a few months. Turns out the brushes were in backwards, and the wire was stuck on the shorter slot.

With that said, its not easy to route the brush wire properly without touching the case, but it is possible. Also, you might need to "adjust" the brush housing so the brush slides thru without any resistance or catching up.

Another thought---have you fitted new brushes? I have found that some (well actually, most) of the 'pattern' brushes are very slightly too big. I have had to, on occasion, give new brushes a light sanding with fine wet-n-dry paper (on a flat surface) on sometimes 3 of the surfaces---it is not really possible on the 'wire' side.

 

[Bounding Bambino]

The brushes in this starter were relatively new. I ordered some new brushes to have on hand. But i found the bush to be slightly stiff when running thru the holder. Agreed, a slight sanding of the sides makes it slide well.

 

[Luke W]

Thanks for all the replies. I took out the brushes and put them back more carefully, I think the wire from the brushes were contacting the housing. Anyway, everything is now working.
Thanks again,
Luke