Atco Commodore B17 - end float on sprocket?

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greswolde
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Atco Commodore B17 - end float on sprocket?

Hi,

Having removed the cylinder for regrinding, I'm currently doing a partial refurbishment of the drive system on my Atco Commodore B17. I've noticed that there's quite a bit of end float on the clutch boss/sprocket when installed (item 11 on attached diagram) and have measured this at about 30 thou (imperial). The clearance looks to be determined by the tufnol washer (item 13) so there doesn't appear to be any obvious way of adjusting it.
So, my question is firstly what level of end float would be acceptable here, is 30 thou too much? Secondly, if it is too much, does anyone have any suggestions on how to reduce it?

I'm planning on replacing the chains and clutch (I have a used/good replacement) and generally cleaning/lubricating. Any other advice on work to do while I have things apart would be appreciated.

Thanks in advance

Regards

Mike   

wristpin
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I wouldn’t worry about it,

I wouldn’t worry about it, but if it bugs you a thin shim washer will sort it. Over the years that pattern of clutch was used the biggest issue was owners overtightening the chains to the detriment of channel in the friction plate and the hardening on the hub. If it’s not gone too far an extra ball or two may sort it ; remembering, pack them in tight, then remove one.

greswolde
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Thanks for the advice, much

Thanks for the advice, much appreciated. I can see exactly what you mean with the spare/used parts I have acquired. These aren't in such good condition as the originals but the friction material on the latter is almost worn out. Ideally, I'd like to reline the original plate - any suggestions for how best to go about this?

Regards

Mike

wristpin
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I’ve never done it and I

I’ve never done it and I haven’t worked on a Commodore or it’s De Luxe predecessor for a long time and can’t visualise the construction of the friction material . The good news is that as that design of clutch has been around for a long time it shouldn’t be too difficult to find a better chain wheel. That said, I can’t ever remember changing one due to worn friction material; completely trashed ball track, yes, but not worn  friction material.

 

greswolde
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Thanks for the further advice

Thanks for the further advice Wristpin. Another question I'm afraid - are there any guidelines for setting up the throw-out on the traction clutch (set by the grub screw - part 28 in the diagram). If this is too loose then the sprocket flops around a lot, but too tight and it tends to get dragged round by the pressure plate. I'm struggling to find a sweet spot in between.

Regards

Mike

wristpin
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That centre screw with the

That centre screw with the locknut just compensates for wear and gives fine adjustment to the clutch push rod. With the drive engaged, ie with the pressure plate clamping the sprocket to the back plate, screw it in finger tight, back it off a turn and do up the locknut . When the drive is disengaged the sprocket should then be just unclamped and cease to drive.

greswolde
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Thanks - much appreciated

Thanks - much appreciated

Mike