Gearbox leaks

[BrianDowning]

I've located and fixed the large leak from the head gasket and I'm moving onto the gearbox. I was told that it had been overhauled some time ago, however It has multiple slow leaks from around the case and from most of the places where gear shafts go through the case ends

I'm guessing that I need a full set of gaskets and seals. Where is the best place to get a kit? I don't see one on the AMOC site. The gearbox has M2994 stamped on it.

Regards, Brian

[Andy.S]

The club spares do parts for your gearbox but under separate part numbers
http://archives.jampot.dk/book/Workshop ... manual.jpg
see drawing in link then check stock and order from club spares.

[spookefoote1956]

I found that using semi liquid grease in my Burman box cured most of my leaks

[BrianDowning]

Is this a Burman gearbox on my 1961 Model 8?

[g80csp11]

semi fluid grease should only be used on CP boxes upto about 1948, oil is a far better lubricant and with good seals and gasket sand o rings the box should be pretty much oil tight
the answer is no its a AMC box

[BrianDowning]

Thank you all for your answers!
Brian

[ChrisTheChippy]

Do not use grease in a lightweight gearbox! This is because the gears sit high in the box and they would get no lubricant leading to premature failure . Good idea to tackle the leaks for the same reason .
I used 3 bond for the main gearbox case . These gearboxes run with a lot of end float so gaskets are not essential.
Mine doesn't leak from the case but from the kickstarter shaft and the gearchange lever . Very frustrating when I took so much time to assemble it carefully.
I know the club now supply an improved seal so I will be trying that although I don't hold out much hope.

[BrianDowning]

Hi Chris
Can you please explain end float? Mine is leaking from all three shafts. I'm wondering if your leaks and mine are due to wear over the years (rather than worn seals).
Brian

[ChrisTheChippy]

End float just means the side to side movement of the shafts within the cases . When you say yours is leaking from all 3 shafts so was mine. There is a seal right at the back of the gearbox ( where the sprocket goes ) that often gets neglected as it requires a major strip down to get to it. That's the only one that doesn't leak on mine despite renewing all the seals when I stripped it down. I'm not to sure if the club stock this seal now. They didn't when I did my gearbox and I got mine from Villiers spares . I am going to have another go at the front seals with the improved ones from the club spares but these gearboxes have a reputation for leaking so it's an uphill battle. They rarely leak from the cases if carefully put together. I used 3bond and left it for a week before filling with oil. Ihad virtually no wear in my gearbox so I guess it had been kept well topped up with oil . Gearbox bits are quite hard to get hold of for lightweights. I would be interested to know how you get on.

[BrianDowning]

I've got the front cover off. There are two pressed bushings plus o-rings. The o-rings on the gear shift are worn. Oddly, the leak on the kick start leaked from the inside of the shaft. The rear shaft (chain gear) leak seems to be from an interior seal as opposed to the outer (probably pressed) fitting also. Haven't got it apart though.

Brian