Gear drive generator

Hello fellas havent been on here in a VERY VERY long time but ive been working on tractors and the old cat 22 and finally got it running while back. I have hit a snag on an antique minneapolis moline GT tractor and thought someone on here may be able to help? this tractor is a 1939 model gt and has a rare starter/ gear drive generator on it and my generator is completely gone. i found another one today but it wasnt for sale but i was able to take it out and get some info and numbers off of it. It is a Delco Remy model 939S, and the gear is a helical gear that is 3.25" in diameter and has 28 teeth. well i was told from the local generator/starter shop that this number was also on the same era cat's such as a D2, R2? i was wondering if this was correct and if there may be a chance that someone has or may know where i could find a generator for sale? any and all information would be greatly appreciated. Thank you so much!!!

If in fact that is the case try contacting John at http://www.tractorparts.com/

Kevin

I'm not aware that Cat used any combination starter/generators.

i do not need a starter i need a generator sorry for the wording

If the drive gear on your generator is OK it might be easier to just have your generator rebuilt, and perhaps converted to a 12v system. That is what I am having done to my CAT22 generator. I found a truck service shop that can have this done. Ray

i do not have a generator at all i used another persons for the information.

939S is a good number:
Specs indicate 4.6-6.0a field current at 6V
Amp. rating of 15-17 and 8.0-8.2v @ 1500rpm cold
9-12a and 7.3-7.6v @ 1600rpm hot

The motor end is probably typical of other applications but the drive gear is going to be unique to the MM units.

Cat drive gears of the era are typically 26 tooth.