AMC Gearbox

[Bird dog]

Hi Chaps. I am currently at the Isle of Man for the Manx GP on my Matchless G9 (1956) fitted with an AMC gearbox (1960ish) of which I am experiencing trouble changing down rom 3rd to second gear by the use of my foot. I can stop the bike and jiggle the gear lever up and down to eventually engage them, to continue my progress for the same scenario to start over again.

This palaver started after I changed the 'O' ring on the gear lever shaft. There is nothing to suggest that the 'O' ring is the cause of the problem as the ratchet falls and flops up and down unhindered, in fact one could surmise that there isn't an 'O' ring in situe it is so free in its movement.

I have had the front cover off over here on the Island without finding the root cause of my dilemma so I am asking the Club community for some sound advice as to what the problem may be with a view to rectifying the gearbox possibly before we leave on Friday 30th of August.

Your thoughts on this irritation would be most welcome.

Kind regards.

Paul.

[Greybeard]

Good morning, Paul.
If this problem has only started since you replaced the seal, it might well be that youve put the long hairpin spring back on the selector upside down. It has one cranked arm which should be nearest to the bottom of the gearbox. Whilst it will work after a fashion when the wrong way up, it isnt consistent - dont ask me how I know

Steve

[bob121]

Yeah, I would say the same. My box now works as it should. After correctly orientating the spring.

[Bird dog]

Hi Guys. Many thanks for your speedy replies.
I have in desperation tried the cranked spring "right way up" and also inverted to no avail. We had another do with the end cover last evening. Due to the fact that there isn't any perceivable wear on the pawl or it's partner in crime, the ratchet, we slackened the gear lever mechanism screws and pushed it the wee amount of slack it had in the opposite direction .5mm approx. We then sett the gear lever pedal as close to the outer shell as possible to minimise any slop in that area.
A minor improvement has occurred whereby the gearchange has become manageable but is not as it should be, with coaxing going from third to second and first being a little bit less frenetic.
The latest thinking we have arrived at is the bushes in the inner and outer cases that support the gearchange shaft are worn to allow enough movement to cause the erretic gearchages.
Once I get the bike home, I will address these issues and sort this problem to a possitive conclusion and post my findings up on this site for our members deliberations.
Racing today here on the Island, and breakfast is beconning. Bacon butty anyone?
Woah!!! form a queue.
Regards.
Paul.

[bob121]

I have had to renew the plunger and spring, also the pawl. This has sorted my issues out, once I put the hair pin spring back in correctly. My pawl didn't have any obvious wear, but did make a difference.

[raffles]

Hi Paul
I recently had a gear change problem. Striped the gearbox could find nothing wrong except some
play in the outer cover selector quadrant bush, replaced bush no more problems
(it had been difficult to get out of first gear)
Tony

[Bird dog]

Hi Chaps. I have sent a substantial reply to this topic to the drafts option, can some kindly member explain to me how I can retrieve it so that I can post it as a conclusion!!!!!!!!!!!!
Kind regards.
Paul.

[Bird dog]

Panic over, drafts page found, EMPTY, aaaaaargh!
It's 23.47 now so I will do it in word and copy and paste it asap!

[clive]

Been there. Now write long entries in word and copy and paste!

[Bird dog]

Chapter IV. Third draft!!!!
Clive. Thanks for your support, I just new that my uniqueness was a figment of my imagination so I am amongst fine company.
To continue with the AMC gearbox saga.
Firstly, thanks to all of those chaps who have responded to my plight.
Desperate men do desperate things when they are far away from home on the Isle of Man, so this desperate man found Allan at RGM in Cumbria and phoned him. (a nice informative chap).
Allan explained that the pawl spring needs to be touching the pawl behind its centre line to be effective which made sense.
I did this and made it worse, (rubbish technique on my part!!) but I always carry a spare (don't ask me why!) I could only go down the box to fourth and there it would stay. Quit the opposite of Raffles who had an issue in first.
Onward and upwards as they say.
Then whilst struggling with a worse condition than when I started, staring into the outer case looking for the bike fairy fount to guide me to my salvation I noticed play at the point whereby the pawl change lever underside pin is straddled by its return spring by about 1mm in both directions.
As bob121 has stated there isn't any one item that can be seriously pointed at that will shine the proverbial light into dark areas and convince us that this is where the problem lies.
So, in the absence of anything else we can accuse of causing the mischief, I pulled out my trusty “Snapon” adjustable pliers that have never been called up for duty before and proceeded to squeeze the offending return spring legs together summoning as much strength as my hands could muster.
Assembled back together without any play, I tested for operation through the box and back again, everything appeared to be “A” OK. Only a test ride would confirm my efforts, (keep with me we are near the last lap)!
Bimbeling along the prom here in Ramsey (the one that they held the sprint on today, Thursday) I tentatively prodded the gear lever from first to second, third was in residence, so to was fourth, were flying.
Now for the hard bit.
Pedestrians ahead need to locate third, click, engaged neatly, braking and engage second, click, where have you been hiding all week! Next thing first was not to be left on the naughty step and once past neutral slipped in as smooth as you like as if coated in PTFE. Full house, such euphoria.
I was so chuffed I made a noise all around Ramsey inner roads and took in the elation before I headed back to tell lady wife the good news. (she had just bought some new bike boots for the trip and could now see the prospect of using them!!!)
This all happened on Tuesday before we where due to go to the “Famouse Creg ny Baa” to watch the racing. Brilliant!
The Matchless performed faultlessly throughout the journey, what a team.
Through the Club membership the Creg do may not have happened in the time frame. The membership rallied and elicited their thoughts and wisdom within this forum and helped me to eliminate the possibilities that could have been causing my problem.
After reading the replies to this forum I will fit some new springs and bushes to the outer case and make it much less likely to be a problem. In my lifetime anyway!!!!!!!!!!!
Many thanks to you one and all, got to get packing for the trip back home in the morning.
We are expecting 40 plus miles an hour wind whilst aboard the Mannanan!! Where are the Kwells?
Kind regards.
Paul.