Broken Down :(

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
markwhitelock
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Broken Down :(

Post by markwhitelock »

:headbang:

My ‘56 G80 has let me down at the side of the road for the first time :cry: I had a strange ratchet sound coming from the gear box (I think), gears were selecting ok but when I pulled away I was getting clutch slip. Pulled over and checked the movement etc, I can't see a clear reason why the clutch suddenly started slipping. New plates in recently. If I put it in gear and pull in the clutch lever whilst rotating the rear wheel it is making a terrible ratcheting sound. It only seems to make it when the clutch is pulled in.

Waiting on the RAC, any advice in where to start investigating would be appreciated!

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clive
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Re: Broken Down :(

Post by clive »

Does not look as though the kickstart is returning. If the quadrant is still engaged the small gear on the end of the main shaft will make a ratcheting noise once the gearbox is moving. Broken kickstart Spring? As for clutch slip after fitting new plates, could they have bedded in and Spring adjustment now needed?
clive
if it ain't broke don't fix
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clive
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Re: Broken Down :(

Post by clive »

Oh and good luck with getting it sorted.
clive
if it ain't broke don't fix
markwhitelock
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Re: Broken Down :(

Post by markwhitelock »

From the sound it is making, it seems to be coming from the rear chain area, I'm wondering if the bearing there has gone? Could that lead to the clutch slipping? The main shaft is a little bent as well so I may as well take the opportunity to strip the gear box and replace that.
SPRIDDLER
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Re: Broken Down :(

Post by SPRIDDLER »

markwhitelock wrote:
.....strange ratchet sound .......gears were selecting ok ...... getting clutch slip...... terrible ratcheting sound when the clutch is pulled in.
Clutch basket nut coming undone?
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markwhitelock
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Re: Broken Down :(

Post by markwhitelock »

The more I'm looking at it and tinkering, I'm thinking that possibly the cush drive on the engine sprocket has come loose and causing it to slip there. Wont know until I get it home and look. I had an issue before where the nut wasn't tightened enough but I adjusted that, I don't quite know how it would loosen with that big spring on it...
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Pharisee
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Re: Broken Down :(

Post by Pharisee »

I had a G9 a long time ago that let me down in similar circumstances. That turned out to be the clutch hub... the splines that located it onto the gearbox shaft had stripped and the hub was just spinning on the shaft.
More recently... I stripped the primary dive off of my G80CS a couple of weeks ago to replace a leaking gearbox oil seal. The splines in the clutch hub on that had been 'hammered' until they were only half the thickness that they were when new. I replaced it with a new one from the club spares as it would have let me down eventually.
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Jdraper
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Re: Broken Down :(

Post by Jdraper »

Does sound like the clutch basket splines had given up.. My clutch was going that way last time I looked, so fitted a centre that was in better condition. Not sure how much play is acceptable on the clutch center/gearbox shaft, but this area is always going to get hammered. New clutch centres are not that expensive - mainshafts are!

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markwhitelock
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Re: Broken Down :(

Post by markwhitelock »

Thanks for all the advice, I took the clutch apart and didn't see anything that looked worn, I then took the rest of the casing off and found that the nut on the primary drive was loose.

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I had tightened it up with an air gun to ensure it was nice and tight, it seems it wasn't! What did I do wrong? I could put a load of locktite on there but that to me just seems a way of hiding the problem! The workshop manual just states to tighten, what tips do people have?

Cheers
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ajscomboman
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Re: Broken Down :(

Post by ajscomboman »

If you're certain nothing else is adrift then threadlock it. They do have a habit of unwinding that's why so many outer covers have been welded as the nut has bored through the dome.
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