gearbox

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chris goldson
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gearbox

Post by chris goldson »

How can I identify if the gearbox on my 1956 model 30 is Burman or AMC please?
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clive
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Re: gearbox

Post by clive »

If it is Burman B52 it will have a little wheel which shows the gear you are in and a screw in oil filler cap. If it is AMC it will have a moulding with the gear numbers on it and a pointer to show which one, the oil filler cap will be held in place by two small screws. If it has neither gear indicator it will be Burman CP (which had two pointers to show neutral.)
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chris goldson
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Re: gearbox

Post by chris goldson »

Thanks Clive I don't think there are any indicators on it but will have a look in the morning. Definitely screw in oil filler though.

New to AJS but someone told me to avoid the burman box as not as good as AMC !!
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clive
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Re: gearbox

Post by clive »

The AMC box ame in in 56 i think
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chris goldson
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Re: gearbox

Post by chris goldson »

Was given some photos with the bike of the gearbox but hard to make out the numbers. Looks something like 26C5 8766 if that makes any sort of sense.
Mick D
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Re: gearbox

Post by Mick D »

chris goldson wrote:someone told me to avoid the burman box as not as good as AMC !!
Hi

As Clive says, if your box has a threaded oil filler cap it will be a Burman box, once you have a better report of the serial number you will be able to determine more details.

The AMC box was regarded as an improvement over the Burman but that's not to say that the Burman had any major drawbacks, they made over 160,000 of them, a lot of which are still giving good service today, 60+ years later.

Of the two, the Burman is the easier to work on and requires less special tooling.

Regards Mick
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clive
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Re: gearbox

Post by clive »

Numbers, if it was 56 rather than 26, then look like Burman numbers. Threaded filler cap for the oil will confirm. If there is no little number wheel it may be missing. You can confirm if it is the later Burman box by looking at the clutch cable entry. The earlier box the cable enters from behind, for the later box the cable enters from a forward position.
I would agree with Mick that the Burman box is quite serviceable, I have all both types on various bikes and they seem to go on for ever without much work. The clutch fitted to the later Burman boxes can make it more difficult to get into first cleanly but this is usually due to wear on the clutch basket internal tangs making the plates stick.
The AMC box gives better gear changes in my experience but both Burman types work well enough, they just need a bit of time to let the gears catch up before the change is completed and I expect you won't be racing your Model 30 off at the lights!
clive
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chris goldson
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Re: gearbox

Post by chris goldson »

Just looked in garage and numbers are as follows:

GB26C56 and B755 if this helps.

Many thanks for all the help
SPRIDDLER
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Re: gearbox

Post by SPRIDDLER »

It's Burman B52 originally fitted to a '56 Model 30

See page 2 here:

http://archives.jampot.dk/technical/Tra ... umbers.pdf

Some years ago we had two Plumstead testers at a club night who recounted that when the AMC 'box was developed they were sent out and offered a fiver if they managed to break them.
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Mick D
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Re: gearbox

Post by Mick D »

SPRIDDLER wrote:It's Burman B52 originally fitted to a '56 Model 30
Bonus - Potentially the bike's original gearbox - time to get the frame and engine numbers to the Dating Officer for a guide as to whether you have a 'matching numbers' bike.

Regards Mick
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