AMC clutch spider binding on sleeve gear.

Information relating to the Matchless G11 or AJS Model 30 600cc twin
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AMC clutch spider binding on sleeve gear.

Postby numbersix » Wed Jul 08, 2020 1:09 pm

I bought my 1957 G11 as a 'project' which was running and the AMC gearbox worked. When it came to dismantling the primary drive I found that there was no centre nut on the clutch end of the gearbox mainshaft........
The centre was very tight and it took a lot of effort using the correct extractor to pull it from the shaft.

Moving on to inspecting the gearbox internals, I saw that the sleeve gear bearing was not fully home in the shell. It also had a nice arc ground out of its outer race by the layshaft top gear pinion, due to being proud of the inner surface of the shell.
No big deal, I thought. I am rebuilding the 'box with new bearings etc. so just press-on.

Having rebuilt the 'box and reinstalled it in the frame, I refitted the inner chaincase and started to build up the primary drive. Clutch, engine sprocket, primary chain all in place and tightened and then....I can barely select a gear. A bit of head-scratching, removing the gearbox outer cover etc before it dawned on me and I dismantled the clutch, leaving the centre in place. I found that I could hardly rotate the clutch centre (in neutral) without the gearbox sprocket turning.

I removed the clutch centre nut and used the extractor to pull the clutch centre outwards a tad and this freed everything up. The clutch spider (shock absorber) was binding against the end of the sleeve gear whenever the clutch centre nut was tightened.
This explains why the previous bodger had not fitted the nut........Doubtless it would have been even more difficult to turn if p.b. had actually fitted the sleeve gear bearing properly!

So, could anyone please advise me what could be causing this problem? It seems that the spider sits too far on to the mainshaft; if so, is this because the spider needs renewing?
Could the p.b. have fitted an incorrect mainshaft (a tad and a bit too short??)
Are there different lengths of sleeve gear out there?
Or is it something else..........?

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Re: AMC clutch spider binding on sleeve gear.

Postby 1608 » Wed Jul 08, 2020 6:55 pm

Have responded to the original post on the Help section.

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Re: AMC clutch spider binding on sleeve gear.

Postby clive » Wed Jul 08, 2020 10:16 pm

Best not to double up a post as you will miss the advantage of the answers all being in the same place. Most regulars who are likely to reply will be looking at "view new posts" and not looking at specific posting headings so will find your post the first time. I am therefore suggest any answers are put in the other identical thread.
if it ain't broke don't fix

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