leak from rear of chain case on G2

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
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Woodland
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leak from rear of chain case on G2

Post by Woodland »

Hi, has anybody changed the felt washer behind the clutch on a matchless G2? If so where do I get a new one and whats the best way to go about changing it?
Want to try and stop the small oil leak from the rear of the chain case and this seems to be the problem area
Many thanks in advance
Gary
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Ozmadman
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Re: leak from rear of chain case on G2

Post by Ozmadman »

Woodland wrote:Hi, has anybody changed the felt washer behind the clutch on a matchless G2? If so where do I get a new one and whats the best way to go about changing it?
Want to try and stop the small oil leak from the rear of the chain case and this seems to be the problem area
Many thanks in advance
Gary
The felt seal behind the clutch is more to stop dirt getting in than any oil coming out. There is no seal on the clutch side of the gearbox and any that may get through the bronze bush should end up in the chain case but anyway it will be very very little if any at all. The chain case has about a pint of oil in it and the leak is probably due to the gasket around the case and nothing to do with the felt washer you mentioned, which by the way is a pain in the a**e to replace. The other and more difficult problem is that it may be coming from the rear gearbox seal behind the gearbox sprocket as they tend to leak from there as well. To find out if this is the case get under the bike on that side look up underneath just behind the footrest and you should see the bottom curvature of the gearbox casing and if it is leaking there you will see some oil settled in the recess in the casing. To be sure, wipe it off go for a run or fill the oil up and leave it for a couple of days and check again. These boxes need to be kept full (3.5 pints sae 50) right up to the bottom of that oval inspection plate on the outside of the casing otherwise rapid wear of the box will occur. This puts the oil level right up over the output shaft seal so any wear or damage there will cause it to leak. come back and let us know what you find
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
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clanger9
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Re: leak from rear of chain case on G2

Post by clanger9 »

On the gearbox oil level, I always though it was necessary to keep the oil level with the bottom of the inspection cover (that's what it says in the owners manual!). However, I recently found this in a 1960 service bulletin:
Screen Shot 2018-09-08 at 13.40.20.png
If you're suffering from gearbox leaks, try running the oil a little low. I've found this works just fine and stops the dribbles.

Likewise, if you run the engine oil level too high, it will chuck oil out of the breather. The correct level is 1" below the filler cap after the engine has been running. That bit is important as the oil level in the tank tends to go up after the engine is started.
Screen Shot 2018-09-08 at 13.46.11.png
I had always run mine higher than this and it used to throw oil out at high speed. Now it's fine.
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Expat
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Re: leak from rear of chain case on G2

Post by Expat »

Woodland wrote:Hi, has anybody changed the felt washer behind the clutch on a matchless G2? If so where do I get a new one and whats the best way to go about changing it?
Want to try and stop the small oil leak from the rear of the chain case and this seems to be the problem area
Many thanks in advance
Gary
Further to the advice already given and assuming the set up is the same on a G3 (I could be way off here), I used to persist in filling the chaincase up to the lower edge of the chain, as seen through the inspection hole. This being the generally accepted level, or so I thought.

Bike persisted in chucking oil out, all over rear wheel and tyre, with a good pool on the ground after stopping and the the response given to my desperate pleas for advice here helped to pin the leak down to the felt seal, ending with, ‘don't worry about filling up to chain level, there will be enough oil and oily mist in there to do the job'.

I did buy a replacement felt seal assembly from club spares I think, but still haven't fitted it as the amount of work involved just to do that alone, with no guarantee of lasting success, doesn't seem worthwhile.

It also seemed to me that on careful examination with the outer cover off, of the relative positions of the lower edge of the chain as it engages on the clutch and the theoretical oil level as seen through the inspection hole will mean that some oil will be flung around even if the level appears low.

Just my 2p's worth, waffle maybe but feel better having got it off me chest! :lol:

Also interested in what you may find.

Steve
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Ozmadman
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Re: leak from rear of chain case on G2

Post by Ozmadman »

clanger9 wrote:On the gearbox oil level, I always though it was necessary to keep the oil level with the bottom of the inspection cover (that's what it says in the owners manual!). However, I recently found this in a 1960 service bulletin:
If you're suffering from gearbox leaks, try running the oil a little low. I've found this works just fine and stops the dribbles.
Interesting!! I fitted a new seal when I did the rebuild but still get a little bit from that seal but!! it seems to make sense as once it drops a tad it stops leaking.
clanger9 wrote: Likewise, if you run the engine oil level too high, it will chuck oil out of the breather. The correct level is 1" below the filler cap after the engine has been running. That bit is important as the oil level in the tank tends to go up after the engine is started.
I had always run mine higher than this and it used to throw oil out at high speed. Now it's fine.
I have an enclosed chain guard so the chain gets a good lube, a bit does come out of the drain hole in it though now and again
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
Woodland
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Re: leak from rear of chain case on G2

Post by Woodland »

Thanks for the information guys, but I would still like to change the felt washer, do you know where I can get one of these? Also has anyone got any useful tips for changing it?
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Expat
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Re: leak from rear of chain case on G2

Post by Expat »

Woodland wrote:Thanks for the information guys, but I would still like to change the felt washer, do you know where I can get one of these? Also has anyone got any useful tips for changing it?
Try the club spares site.

http://www.amoc-parts.com/store/comersu ... duct=23700

910101 FLOATING SEAL KIT
Hope the link works.

Steve
Keep shiny side up.

These are my principles, if you don’t like them, I have others. (Groucho Marx)
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clanger9
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Re: leak from rear of chain case on G2

Post by clanger9 »

Yes, that's the one. There is more info in this thread:
http://www.jampot.com/forum/viewtopic.p ... 26#p195765
1989 Moto Morini Dart 350
1993 Ducati 750SS
Woodland
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Re: leak from rear of chain case on G2

Post by Woodland »

Many thanks for this information, but I managed to drill out the old spot rivets, then made a new washer (from leather). I soaked the washer in oil overnight.
Next step so to put back together, I just rotated the disc until the old holes did not show and re spot welded, looks a good job

Will let you all know if this works
Gary :D
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