I'm working on a young kids Monte Carlo SS.The starter bendix went out and the starter runs with the key off.I got lucky and got the neg cable off in time before it killed the battery,destroyed the flex plate.I have replaced starters in the past that the bendix went out but I have never taken one of those starters apart,I just throw them in the garbage and forget about the core charge.The young kid asked me,what happened inside the starter set by set as it failed and everything started melting.I told him the starter drive kicked forward and the solenoid would not release it and he is asking me why the starter part burned up.Anybody have any ideas on how the starter burns up inside, from start to finish when the bendix goes out and why won't the battery go dead without destroying the flex plate if you don't get a battery cable off in time?

If you take the solenoid apart you'll probably find the copper disc welded to the "BATT" post. That will cause the drive to stay engaged in the flywheel. If you leave it long enough, the battery will eventually run down.

#1 the starter generates a ton of internal heat while cranking which would explain the internals burned up during prolonged cranking. If you ever lookid inside a starter while its cranking you'd note that there are lots of sparks between the brushes and the commutator while its cranking. Those sparks are hot. Eventually they will cause the copper of the commutator to melt and run. This causes the indivitual commutator bars to become connected to one another. Thats causes shorts between the starter windings destroying the starter. That damage can be cleaned up but you need to know what you are doing to do that.


With respect to the flex plate it takes no time at all for the bendix drive to chew the
teeth off the flexplate.

That would take out the armature,but what is going on that melts the field coils.The wires to the brushes are burned in half and the starter still keeps cranking.I'm guessing that at this point that is what takes out the battery to were it can not be recharge.Were is the commutator getting its power when the brush wires are melted.Is it possible for the field coils to be cranking the starter while it is shorting out at the commutator?I'll give you an idea of were I'm coming from.On a 71 Cutlass,I shut the key off.The bendix went out on the starter and the starter cranked at normal speed for about 10 seconds and then speeded up so fast it sounded like I had no compression and as it speeded up the dash lights started flashing.It cranked for about 90 seconds and then nothing.The headlight switch was off all this time.I am thinking that when the lights on the dash started flashing,the brush wires were already burned in half because the starter was cranking past its normal speed.The heat should have slowed the starter down but something speeded it up.What made the starter speed up,could it crank through the field coils.I replaced the starter and battery and the car was fine.

This might not be related, but I read that on a engine with a coil/distributor setup, if you don't have a good electrical connec tion between the NEG on the coil and second connector on the solenoid, the starter will stay engaged when the ignition key is released. That's my 2 cents....LOL

The NEG on the coil only goes to the points and has nothing to do with the starter operation.

Chevelle starters do not have a "Bendix" they have starter drives.
Fords have a "Bendix"

IF the starter drive gear gets stuck in the flywheel ring gear it will hold the solenoid in the "engaged" position.

My wiring diagram for the 68's shows a wire from the coil to the starter (POS or Neg I can't remember for sure)

My wiring diagram for the 68's shows a wire from the coil to the starter (POS or Neg I can't remember for sure)

There is a POS bypass wire connected from the Starter Solenoid's "R" terminal to the coil's + terminal that sends a full 12 volt signal to the coil DURING cranking.