Dixie Magneto gear on a 17F

[partshunt]

I am changeing out a scuffy mag driven gear with an NOS gear on an H-D 17F. However, the NOS gear is listed in the parts book as being for Bosch and Berling mags only, identified with three holes thru the face of it, PN 626-18 for 18 and later. The gear I am removeing off the Dixie is a solid style gear shown in the early parts books to 1917. The NOS Bosch gear fits perfectly, so I dont know why it is not shown to fit earlier Dixie mags. I see no problem but am I missing something here?, The taper, key way and timeing mark are the same and located with the same positions. What is going here?...Anybody useing the later gear on a Dixie with success? Thanks, any input would be very much apreciated...Joe

[MMasa]

Have you ran the bike with that old gear?
Mark Masa

[partshunt]

Hi Mark:- It did run for about 10 minutes on start up some years back but the Dixie base shattered right away. As you know they were made from Pot Metal like material. So, it has a new alum base on it now I got from Barry Reeves who casts them. The 17 has been running with a Bosch running with a good gear on it. I picked up the other NOS Gear long ago and just want to install on this Dixie. Fits good, I see no problem. Just wondering if others have done the same as me, useing a Bosch gear on a Dixie..It may be that the parts listing just omitted Dixie info their parts listings in the gear description, not sure as the description only mentions it is for Berling and Bosch. Normally, if a part come out in later years and fit backwards, the books always use the word "fits" such and such a prev yr also, then you know its an update and can be used those mentioned on earlier years....Joe

[Slojo]

" The taper, key way and timing mark "

Joe, it is best to omit using a key on the taper bore gear to tapered magneto shaft. If (when) you have a magneto failure a week point such as gear slippage on shaft can be your best friend.

joe

[MMasa]

Joe is right. It drives off of the taper anyway. The key is just there to automatically time it.
Small world! I just bought a base off of Barry yesterday.
Mark Masa

[LouieMCman]

Are you guys saying you actually run your mag gear without a key in it? Where as I've never ran one 3000 miles at a time, I've never thought of leaving the key out either.

[Slojo]

Louie

Toss the key.

During cannonball I overheated the insulation on my magneto armature. This results in a softening of the tar like insulation to a liquid state, stir in a little centrifugal force and the tar accumulation fowls the field. Next your armature is churning the clinging substance to a point where something must give. My magneto drive gear slipped putting the motor out of time shutting me down without damage. A key in the system might cause a broken magneto shaft or drive gear, possibly the pinion gear, that is bad.

joe

[fillibuster]

Louie

Toss the key.

During cannonball I overheated the insulation on my magneto armature. This results in a softening of the tar like insulation to a liquid state, stir in a little centrifugal force and the tar accumulation fowls the field. Next your armature is churning the clinging substance to a point where something must give. My magneto drive gear slipped putting the motor out of time shutting me down without damage. A key in the system might cause a broken magneto shaft or drive gear, possibly the pinion gear, that is bad.

joe

I'm glad to know others think this way (tapers). When I first encountered tapered bushings in industrial drive components I was taught that a tapered sheave on a tapered bushing was such a sure fit that one could remove the bolts and expect the sheave to stay on the bushing, and endure all the torque it was sized for.
One the Indian Chief the gen drive pulley fits a tapered shaft of about 1/2" with woodruff key, but upon losing the key during a clutch fix (in a far-away pasture) I applied red locktite and about as much torque as I thought the threads could take, and I've run without the key since.

There! a little Indian on your dam harley thread! ....

[Tommo]

Joe
Think about the whole thing in a purely mechanical sense.
If the gear is the same diameter with the same number of teeth, that have the same tooth form, what other things will stop you using it?
The only other things I can bring to mind is are the tapers the same and is the sideways tooth mesh correct.
If all these things check out there is no reason why you can't use the gear but you should check the tooth backlash through a complete revolution of the gear once its all fitted up
Also make sure it doesn't foul the inner and outer cases at all.
I thought the only difference was the three puller holes in the gear and that these were introduced to stop people damaging the cases trying to pry the gear off.
If you were to fit the gear I'd be getting those three puller holes put in because when you need to remove the gear at a later date, no holes wouldn't bear thinking about.

[partshunt]

Tommo, yes from a mechanical point, you are exactly right. I am 100 % sure it will be fine. I was just asking if others are running this gear on their Dixies. It is a 1918 and up gear listed for Bosch and Berling. just dont know why the parts book didnt state it was good for the earlier years when Dixie mags were used like on my 17F. Every physical feature matches just fine. The only physical difference is the hub face for the nut as it is not flush with the gear itself but that doest matter a rats #$%^. This hub is relieved about .030" below the gear where on the old solid gear the hub is flush. The three puller holes are an update for sure and I see your point there. Its gonna go in fine , the teeth are the same and afterall. it is listed for the early Harley gear train anyway. a very nice NOS gear at that. Thanks to all for your reply and sugestions...Joe