Gearbox Concern

[bike63]

Hi there, Has anybody needed to replace the output 4th gear (sleeve gear) due to the bearing track (runs in roller bearing) being worn - if so where did you find one ..... also the roller bearing and oil seal ? I'm told these gearboxes will run OK with a fair bit of wear here and there. The rest of the components look alright.

[56G80S]

What gearbox is it? AMC or Burman and if the latter, CP or B52?

Johnny B

[DM2]

Probably neither as it's in the G5 / Model 8 section.

What gearbox is it? AMC or Burman and if the latter, CP or B52?

Johnny B

[56G80S]

Sorry, I only ever click on the "Recent Topics" and hadn't looked at the section, however, it is therefore an AMC gearbox in the main. Or was when I rebuilt one all those years ago.

Johnny B

[clanger9]

If the track is worn, you have a couple of choices - both tricky!
1. Find a replacement output gear in good condition.
2. Machine the bearing track down, harden it and fit an undersized bearing.

There is some useful info in this thread:
http://www.jampot.com/forum/viewtopic.php?f=15&t=24221

[dodger]

You could investigate having the track hard chrome plated and ground back to the original size.
amphardchrome.co.uk advertise this service and they can mask so that only the worn area is plated.
Worth giving them a call if all else has failed.

[Steve S]

Part number 044075?

I bought a NOS one from Norvil 2 years ago, pricey though!

Steve S.

[bike63]

Thanks for your responses -
Ideally a good replacement , but hard to find (rare as hens teeth as they say)- Steve S your part number is different from that in my manual, but I could try Norvil.
The machining/plating is something I'll look at.
If the roller bearing is worn perhaps I could simply replace that which might compensate a little ? - but the cheapest I've seen is £60 ... the SKF one is £75 (Simply Bearings) - might be a daft idea ?
Last bike I restored was a BMW 25 years ago - all metric and easily available parts - good job I enjoy a challenge.
Cheers, John

[Steve S]

Hi, the main sleeve gear 044075 is the replacement for the original 041273 which had round pegs, which when worn led to jumping out of top gear. The manual (on page 51) refers to replacing this with 044075 which has undercut dogs and which engages with the new replacement sliding 3rd gear 044076 which is itself very hard to find although Ozmadman and myself found that Andrew Engineering had a box full of new old stock ones, but he has now sold out and I don't know who bought up his stock (this club maybe?). You need to replace them as a pair or else persevere with the original peg types ones. Steve S.

[Steve S]

Re my post above, it implies Andrew Engineering had sold all of the 3rd gears, I believe he still had some when his business was sold. Sorry for the confusion caused!