No 4th gear in AMC gearbox?

Has the gear selector quadrant been adjusted correctly? There was a bit in Roadholder about this fairly recently ... sorry I cannot remember how recently.

Ian

Previously wrote:

Thanks Ian, I was able to get the info on that & set it up accordingly. The forked gear slider has a dowell that rides in the camplate, it doesent seem to want to go round the bend in the plate from 3rd to 4th. The dowell & the plate seem to be unworn & I have also tried switching forks ( they are identical, same part number even) to see if anything changes. I am at a loss. This bike has been out of commissio for 35 years.

Skip

My next suggestion would be to give Dale Middleton a call. His number is in Roadholder as part of the Tech Team.

Ian

Can you select 4th gear manually by moving the quadrant lever with the outer cover removed? If you can then the fault is with the footchange selector ratchet mechanism. If you still can't maybe you have the leverone tooth out on the quadrant. You say you know how to set this and so you must have checked the correct position. The only other likely problem is that perhaps the 4th gearcog is reversed?

Les

Previously wrote:

Hi,

I have a '57 model 77 with an AMC gearbox. I had my local Brit bike shop do the rebuild for me to give them some buisness. I now have the gearbox in the frame & was turning the gears via the kickstarter & I cant get a 4th gear? Any thoughts of what to look for?

Thanks,

Skip

After stripping my gearbox and re-assemberling it I had the same problem but this time it was 1st gear, on a close inspection I could see the quadrant was hitting thebottom of the slot it pokes through in the inner cover, I moved the quadrant back 1 tooth on the cam plateand this solved the problem.

See the quadrant is not hitting the top of the slot, if it is move itforward 1 tooth.

Use the bolt holding the cam plate to turn the cam. hope this helps

Ian B

Previously wrote:

Can you select 4th gear manually by moving the quadrant lever with the outer cover removed? If you can then the fault is with the footchange selector ratchet mechanism. If you still can't maybe you have the leverone tooth out on the quadrant. You say you know how to set this and so you must have checked the correct position. The only other likely problem is that perhaps the 4th gearcog is reversed?

Les

Forget the 4th gear cog reversal, I was going from memory. I think it can go anyway round. I was thinking it was offset slightly with a boss one side, but don't think it is like that.

Les

It's funny what you find while surfing around aimlessly. I hadn't thought about Nortons for years and then I found your question somehow. It's fairly recent so if you haven't sorted it yet I'll put in another suggestion.

If the layshaft bearing is not fully home, say it's been loctited and not gone all the way in, or the housing is chewed or there's some swarf behind the bearing, then it limits the travel of the selector fork, leading to the symptoms described.