Parts wanted

[carl denton]

Hello looking for 1 gear for my 1915 Douglas 2 3/4 hp . Anyone got one they can help me with . 

[Hutch]

Carl,

Is that from a 3 speed gearbox? If so, did it come with your 1915 2 3/4HP originally?  3 speeds on these early machines are quite rare, but some 1915 model W 2 3/4hp's did come into Australia.

The early 3 speed gearboxes used on the 2 3/4hp have 4 "dogs" on the selectors and the later ones (1920 onwards??? up to CW) have 3 dogs - so they are incompatible. I have a 3 speed with serial number 7xx and it had the 4 dog selectors. I'm not sure when they changed but my guess is sometime in 1920 but I could be wrong)

Sorry I cannot help you with a replacement gear.

Often the main shaft on these 3 speed gearboxes has  a longer left hand thread for the adjustable belt pully as opposed to that of say a CW output chainwheel or non-adjustable pulley on a belt drive machine.  I think, other than that it should be possible to use a more common donor CW 3 speed gear set in the earlier cases, but you would need to swap out all the gears and selectors(??) Hopefully someone will come up with a 4 dog gear for you tho'.

(Edit: Note the earlier "four dog" 3 speed gearboxes use feather keyways on the shafts, this is different to the later "three dog)  3 speed 2 3/4hp and CW woodruff keys, but should be able to be adapted moderately easily ??)

Some pictures of the difference between 3 and 4 dog selectors for 2 3/4 HP 3 speeds here;
https://www.douglasmotorcycles.net/index.php?topic=6193.msg22874#msg22874

 I am interested in the serial number of your gearbox (especially if your is one from a 1915/16 model W) for my research into gearbox numbers as I am missing info. on these early 3 speeds.

 https://www.douglasmotorcycles.net/index.php?topic=9253.0
 
 Please PM me if you get a chance.

Cheers

Hutch