1924 6 cyl Starter gear motor clutch

[Oregon Desert model 45]

(1924 6 cyl motor)

There is a double gear assembly inside the flywheel housing that slides on a shaft and engages with the flywheel and Starter-Generator gear when the driver pushes down on the foot pedal. This double gear has is a one way mechanism inside that catches when the Starter-Generator is cranking the motor, and slips in the opposite direction when the motor starts firing.
The parts book called this gear "Motor clutch" or something like that.
The teeth on the small gear had been smeared where they first contact with the flywheel to the point where it would not even engage with the flywheel teeth. I hand filed this burr away so the gear would slide and engage to the flywheel teeth, but did not completely clear the flywheel when turned by hand, and would jam the flywheel. I disassembled the double gear, cleaned up the parts, then chucked the small gear into the metal lathe and cut back the nose of the gear to get some clearance with the flywheel.
I am not really sure if trimming the gear was the right solution to this problem, but the entire linkage - footpedal to Starter-Generator are all moving and operating now when the gears are lined up.
I have wondered if perhaps the legendary Mr Rube Goldberg was employed by Buick as the designer of this overly complicated linkage of plungers & levers !

Question: Should the insides of the Motor clutch be greased heavily or lightly oiled ?  I sure don't want this thing to be ruined if the lubrication is wrong.

 

Kevin
BCA # 47712

 

[ROD W]

Kevin,  Of the ones I have pulled apart,  there has not been grease in them.  Too much grease may clog up  the springs and rollers,  preventing the clutch operating.  I would just use light oil.   

[27donb]

Kevin, I want to thank you for posting the story and pictures.  When I put mine back together, I will pay close attention to the issue you were having to see if I have the same.  Very interesting.

 

And light oil, not grease, that makes sense, thanks Rod W.

[dibarlaw]

Kevin: I will second that thank you. It is nice to see what to expect when working on the 1925-45 when I get it home. When I drove it 2 years ago the starter seemed to engage correctly. The only time my started would not engage on my 1925-25 is when the one clutch disk disintegrated and ended up packing the starter gears.

[JerryVan]

Yes, only light oil, but even dry should be fine. Anything that is heavy, like grease, or gummy, as oil came become, will prevent the rollers from working freely as they should. I would almost fear that even oil might not let the rollers grab as they should, but instead slip.

[Oregon Desert model 45]

I hooked up a new battery to the S-G unit, which performed well in both cranking and motoring modes. Photo below shows the "test" wiring with on/off switch used in lieu of the dash mounted ignition switch to activate motoring. 

Now the bad news: something is wrong, because the small gear on the motor clutch bangs into the flywheel before the big gear engages with the S-G gear.  If the gears are lined up perfectly, pushing the foot pedal slides the motor clutch into place, all the gears mesh, the starter activates and cranks the motor over.  However, the S-G gear should mesh first with the motor clutch so it will be rotating before it engages with the flywheel gear.  If the S-G gear moved forward a little it might just work. maybe the gear on the S-G is not fully seated and is too far aft ?  unfortunately I didn't get a good photo to illustrate this problem.

 

Kevin

 

[ROD W]

Kevin,  It looks as though your your clutch gear and small gear are too far back.  They should be able to move fully forward to the housing so there is plenty of clearance between the small gear and flywheel,   There is a spring in the fork selector ( tower ) for want of a better word,  that returns the gears to there forward position,  maybe this is broken.

[JerryVan]

Kevin,

 

I don't think taking a cut off the end of the gear was a good idea. No matter what's spinning or not spinning, the squared off ends of the gear teeth will make it very difficult to get the gear in mesh with the flywheel. Notice that the gear originally had the teeth angled off at the ends, where as your modified gear is squared off.

 

 

 

[Oregon Desert model 45]

Rod

My motor clutch is as far forward as it will go in the photo, and your picture perfectly illustrates what it should look like.  thank you.

Mine is probably from an earlier year that did not interchange with 1924-1925 models.  One of the hazards of working on an incomplete car that has been assembled from parts collected here and there, is not everything fits.  This motor was in pieces when my father bought it back in 1984, so there was no certainty that all the parts were originally from the same motor.

Kevin

[JerryVan]

Kevin,

 

I understand when you say that's as far forward as it will go, however, my question is, what's preventing it from going farther? Nothing in your photos show what's interfering.

[Oregon Desert model 45]

Jerry

the small gear hub appears to be longer on this unit, and it hits the aluminum housing.  I didn't see any identifying part marks stamped anywhere on it.

 

Kevin

[Oregon Desert model 45]

I have identified what was wrong with the motor - it had a flywheel from a 1921-22-23 6 cyl, which was 1/4" longer than 1924 6 cyl/1925 Master flywheel.  The other obvious clue that something was wrong was the inside diameter of the flywheel should fit snugly on the end of the crankshaft, but the ID of said flywheel was much larger than OD of crank end, so the flywheel is just hanging by the bolts.

Hindsight is always much clearer !

 

1st photo below showing 1921-22-23 flywheel on left, 1924-1925 flywheel on right.

2nd photo shows the 1921-22-23 flywheel not fitting snugly over the crank end.

 

Kevin