Cat D6C Starter Pinion Adjustment

As a test I wired the solenoid to my batteries to ensure the sol was actuating and causing the pinion to travel. I did not connect any wire to the starter motor windings because my wire is too small and I don't think that's a problem anyway. So after touching the wire to the battery I hear the sol actuate but there is no resulting travel. I then adjusted the nut so it was against the smooth shoulder of the sol shaft mechanism. Same result no pinion travel, so obviously that's the problem and am thinking about adding spacers under the but so when the sol retracts the spring can force the shaft out. Any thoughts?


[quote="Beachyw"]Hello All,

Recently I have had trouble keeping the starter pinion engaged while starting. The starter motor spins but the pinion won't stay engaged. I replaced the solenoid because it was suspect and in horrible shape but I still have the same problem. This morning I took the starter off and examined the pinion and plunger linkage assembly. The leading edge of the teeth on the pinion are worn but if think they should be ok provided the pinion is engaged deep enough on the ring gear. BTW I replaced the worn ring gear when I rebuilt the engine. So I'm left fiddling with the engagement adjustment but on the plunger linkage. At least I think it's for adjustment.

Anyone have any advice on how to set this properly, my manuals don't show any of this for some reason.

Thanks,

Wendell[/quote]

mate might want to try the test with starter motor turning over a lot of starter motors require the motion of the starter motor turning for the bendix to shift at all

pictures would come in handy as there are many different starter motor types and I would only be guessing but if your solenoid is going clunk I think it will be ok the bendix or starter pinion will be the problem from what you describe as I have said pictures will come in real handy for people to understand your problem

Paul

I think I attached the pics, first time trying this.

I reinstalled the starter, hooked it all up and tried it again. The starter turns but does not engage the ring gear at all. Just spins. my machine is a 76A with a rebuilt 333. Any advice would be appreciated.

Check your wiring, normally the solenoid has to move and engage the starter drive before making contact that drives the motor.
This is the correct pinion adjustment.

I will check it, does the solenoid alone engage the pinion(via the plunger yoke) or does the rotary action of the motor drive it forward as well?

Thank you!

Solenoid first engages the pinion then cranks the motor. Motor should not be rotating until the drive is engaged to the flywheel and there is simultaneous buss contact to crank the motor.

Diagnosing from afar I'd say the pinion adjustment is out so that the pinion gear bottoms out before buss contact is made and you're running on the solenoid engagement circuit instead of the motor contacts.

Motor may run but it will not have the amperage to handle any load and if left on the engagement circuit it will fry the solenoid winding.

Normally this happens so fast what little power that is applied through the solenoid pull in circuit has little or no affect on motor run.

Here's what going on with the solenoid.

Solenoid first engages the pinion then cranks the motor. Motor should not be rotating until the drive is engaged to the flywheel and there is simultaneous buss contact to crank the motor.

Diagnosing from afar I'd say the pinion adjustment is out so that the pinion gear bottoms out before buss contact is made and you're running on the solenoid engagement circuit instead of the motor contacts.

Motor may run but it will not have the amperage to handle any load and if left on the engagement circuit it will fry the solenoid winding.

Normally this happens so fast what little power that is applied through the solenoid pull in circuit has little or no affect on motor run.

Here's what going on with the solenoid.

There is the possiblity that the starter drive is slipping, the problem was intermitant, and slowly got worse, something to consider.