As we continued to start the engine of my 1925 Tudor recently, the Bendix began to stick. After rocking the car a few times while the clutch was engaged, it released the Bendix and started right up. The second time this happened, a terrible, sort of rattling (and grinding) noise came from the Bendix, and continues. After letting go of the starter switch, the engine would be running. We did this about three more times yesterday before putting the car in the garage. Does anyone have an answer as to what might have happened? Did I lose a gear tooth on the Bendix or on my flywheel? Is it bad to start the car while haring this noise? Should I remove the Bendix and examine it?
I think you will need to remove it and replace or repair it.
André gave you good advice .
I had exactly the same problem about a month ago . Didn't know what was going on suddenly .
André looked at it , took off the bendix cover . The spring was broken and a pin .
He replaced it ( while I was looking = helping ) . Works great now .You can buy the repair kit at Lang's :
p112 of the catalog .
It takes about one hour .First take the pieces out before ordering new ones .
Belgium too .
I had a similar problem many years ago. The engine would start just as I let go of the starter switch, but it would not always start.
The times it did start was from my releasing the starter switch just prior to the cylinder firing and giving the related coil enough voltage to make a spark.
My problem was a very tired battery. The starter took more current than the battery could provide and dropped the voltage level down to where there was not enough current to make the coils buzz. They were not in top shape either, but I did not know about coil problems at that time.
Later, I learned that an easy was to identify if this was the problem or how tired the battery was could be determined by measuring the voltage between the starter terminal and engine metal with the starter switch depressed.
An engine that measures only 40 to 50 psi compression will turn over slowly and often start with only 3 volts measured on the starter terminal when the starter switch is depressed. It will never start as soon as the switch is depressed though.
There should be at least 5.25 volts there. If there is less than that, the battery could be getting old, the cables could be going bad or of a smaller size than the original 0 or 1/0 gauge size, the starter switch contacts could be corroded or the ground connection between the frame and engine could be poor.
There is also a load test set that will test the battery while drawing the current required to turn a starter and provide a voltage level reading on a small meter in the test set.
Take a look at my post and pictures from early July here
I also had a broken bendix
There are some bendix springs wound in the opposite direction, Perhaps early V8's. If you have such a spring on your bendix, it could be unwinding but not broken. If you remove the bendix cover, you can see visually what might be causing the problem. In fact, you could even run the starter with the ignition switch off so that you can see what it's doing. Or you could have someone look in toward the flywheel as another person turns the hand crank slowly to examine the condition of the flywheel gear.
Another possibility would be a bent starter shaft causing the bendix to scrape on the cover. If that is the case, you will need to straighten it or replace the entire starter.
It could be the bushing on the front of the Bendix has unscrewed or it could be a bent armature shaft. The noise could be Bendix bolt heads are grinding on the starter can. Repro Bendix bolt heads are about twice as thick as originals. You should be able to straighten the starter shaft. You need to rotate it between two fixed points near the the ends of the armature windings. To check it, as you rotate it use a straight edge against the far end diameter of the shaft. If its bent the distance from the shaft to the end to the straight edge will vary as you turn it. You should see no more than about 0.020 if the shaft is reasonably straight. You might need to carefully make some V blocks from a piece of hardwood to support the shaft and double sticky tape them to your work bench. If your end supports allow the shaft to move other than rotate then the check is meaningless.