MASCOT May - June 2008

Dear Aunty (gearbox jamming)

I read with interest the fixing of Sidney M Xavier's jammed gearbox woes in the Jan/Feb Mascot. I've just fallen foul of the same trouble myself whilst I had the cover off a Roadster gearbox and somehow got first gear a bit too far back so that the spring loaded balls were half popping out. Try as I might, I couldn't get the gear to move forward over the balls in the syncro cone. I then thought I should consult your Mascot article and study the pictures, which was when I realised that, as clearly shown in Fig 3, it is the Locking Pin being dislodged from its groove, and its ball, that completely jam the assembly and prevent the gear from being moved forward, and that the way to get the gears back to normality is first to move the syncro sleeve backwards, which is the opposite direction to what you might think, so that the peg can go back into its groove. Then you can easily get the gear over the spring loaded balls - childs-play once you have sussed out the dodge. So one screwdriver to move the syncro sleeve back, and another to simply pop the gear back over the balls.

No brute force needed if you know the right way, but I had previously given it a lot of force in the conventional direction to absolutely no avail, and so can relate to Sidney's remark when he said "no amount of heavy handed persuasion would shift it". So thank you for publishing the diagrams and the description which helped me work it out! With the gearbox top on, I don't seem to have a jamming problem, but we wait and see.

Best wishes, Andy Draughtsman.

Dear Andy. Thank you for the story of your gear-jamming experience, which I found very interesting, as it is possible you have provided the answer to why Sidney's 1st gear was going so far back, on which I could offer no ideas at the time. As you have no problem when the gearbox top is on, it sounds as though your 1st gear is being located by the selector fork, which is holding the gear forward away from its stop and so not exposing the detent and locking balls. On Sidney's 'box, a degree of wear in the selector mechanism could have allowed his synchro unit to go far enough back to expose the balls and cause the jam as per Fig 3. However, if Sidney's problems were due to selector wear, which was not apparent, I think it surprising there have not been more instances of jamming. As you say, we will have to wait and see!

Best regards, Aunty.