AJS & Matchless Owners Club

Hello,

This time it is the Speedometer Drive Gearbox
I got a new speedo gearbox and 4 pinions (If that's the right word).
All the pinion teeth look the same but the ends are different in diameter

A -----> Right Fit
B -----> Same teeth but doesn't fit. The pinion ends have a larger diameter.
Please help me with the following questions

1. Is there any difference in the pinions as you can see from the pic?
2. Will I be able to reduce the diameter of the pinion ends and then use the other pinions?

Sorry if my question is very basic but just wanted to ensure.

Regards
PHenry

Your photo is rather small especially on my phone. But after enlarging i have these comments ( numbering from the left) 1 and 2 have pinions for one direction of drive 3 and 4 the opposite one. Sorry cannot remember which will give you clockwise drive which is what you need for an AMC.
If you machine drive 2 and 3 the pressing for the end of the cable, which is the squashed bits, will become too thin. You might get away with 1 as it does not appear to have the compressed bits but to be an earlier type which had a cast square for the cable.
Unless someone else can help you will have to insert 4 into your base unit. Turn the drive as though the wheel was going forward and the cable drive should be turning clockwise when viewed from in front of it. If its anti-clock you will need to consider machining 1.

Not sure if this will help, depends how well focused the original file was. I can only submit and see.
Looked, gone out of focus somewhat. I took it from 500 to 1500 to equal both dimensions. Could drop it back to 1000.

Thanks so much. I did not notice the difference in teeth. Anyways here is a better picture. Hope this will help for a better analysis.
Regards
PHenry

cannot really add anything except the 3rd up from the bottom looks very heavily worn.

The drive is effectively a reversed worm gear and pinion. The worm gear being the ring driven by the wheel. If pinion "A" in the first photo 'fits' then the two pinions on the right hand side won't because they are the wrong 'hand' and cannot be meshed with a worm wheel machined for the two pinions on the right.

Thank you so much for I have sorted this to an extent and everything seems good thus far.
My last 2 questions:

1. Should the pinion have 2 washers on either ends? Are they (1) Steel (2) Copper (3) Fiber (4) Something else?
2. The back plate is supported by 4 Rivets. Are these available easily or is there an alternative?

Thanks so much for all your help in this regard. I'm a step closer to completion.

Regards
PHenry