1i951 G9 CP Box Gear selection

[ChrisD200]

Hi all
Just taken my G9 (Lazarus, for obvious reasons) for along trip. Half way, at ~300 miles, there was a clonk from the gearbox and from that point forward over the next few miles, I could still select gears but top gear saw the gear selector lever hanging down way below my boot-tip. After those few miles I had to go into first but couldn't select it, or indeed, any other gears from that point forward.
Yet the selector was free the whole time - up and down movement and the relevant 'stops' were as normal but no gears selectable. Temperatures at the time were above 37degC (in Oudtshoorn) so I took the easy option of loading Lazarus onto the backup trailer!
It seemed like there could be a return spring to lift the gear selector after each up-or-down movement and maybe that was unclipped or broken. Is that possible or could it be selector forks (there was no violence needed to change at the time of the 'clonk')? How do I test for those without compounding the error by stripping a box for what may be a simple problem?
Any advice welcomed, Cheers
Chris (Cape Town)

[deshollier]

Assuming it is the AMC box. It is almost certainly the gear lever return spring, part number 040075. available from JSL and others. It is cheap enough so get two and keep a spare. It can be changed by removing gearbox cover only. Happened to me on the way to the last Jampot Rally. Changed it on site by laying bike well over so as not to need to lose much oil, Be careful to align the spring arms correctly (check the old one for which arm is nearest to outside of box). Also be careful to refit the gearchange pawl spring correctly when refitting the cover - you can check how it should be by keeping your eye on it through the filler/clutch adjustment cover as you take the kick start cover off. The long arms must locate in the notch either side of the pawl and the cranked arm to the bottom. It will be clear when you look at it! To do a proper job you should also fit a new kick start cover gasket while you are at it, part number 040055. Best of luck. (I really must learn to read! Only just noticed the title - 1951 G9 CP box) (I really must learn to read! Only just noticed the title - 1951 G9 CP box) Edited by - deshollier on 23 Feb 2010 12:25:49 PM

[dave16mct]

If its a 51 G9 it'll be a CP box, but it does sound like the gearchange return spring(s). Never done one on a CP box, sorry. Dave

[wilko]

There's a solid dowel thingamy that works loose in the alloy selector block that works loose. I just cut off a section of appropriate slightly oversized bolt (probably metric) and pressed it in with loctite and it's been good to me for years. It still could be just one of the selelector springs as someone has already suggested tho'.