G: Gearbox (Twin) Unyielding gear selector
- Thread starter phsDommie
- Start date
Thank you all for your suggestions
a) I took the clutch apart - all was very clean and dry (no oil oozing into the clutch) and all spindles are fine. I measured the clutch springs and they match up well. I adjusted the clutch cable as per the handbook instructions. With wheel off the ground and engine running, the rear wheel rolls to a stop when in gear and clutch (handlebar) lever pulled in.
b) Took the outer gearbox cover off - again. Minimal adjustment made to position of G61as per Richardson's book. Adjusted, slightly, the cam (G57) to allow more room by G49 for upward movement of the lever. Found there was a washer under the bolt head (right hand 327) which might have interfered with upshift and removed it.
c) Return springs (G64, G70 and G71) had been replaced with new ones a couple of hundred miles ago and all looked to be in great condition
d) The battery carrier tray is a nice sliding fit with the two slim nuts up against G50. I don't know if that is enough.
e) I drained the gearbox of oil - beautifully clean without evidence of metal fragments, so replaced it via a filter
After all above, I replaced the cover, kickstarter lever, gear selector lever, G81 and readjusted the clutch. I can select all gears, up and down while the engine is off. Started her up and it appeared as if I'd done nothing - same refusal of the selector lever (G78) to even budge in upward direction!
I'm flummoxed, especially since all worked beautifully a couple of months ago.
a) I took the clutch apart - all was very clean and dry (no oil oozing into the clutch) and all spindles are fine. I measured the clutch springs and they match up well. I adjusted the clutch cable as per the handbook instructions. With wheel off the ground and engine running, the rear wheel rolls to a stop when in gear and clutch (handlebar) lever pulled in.
b) Took the outer gearbox cover off - again. Minimal adjustment made to position of G61as per Richardson's book. Adjusted, slightly, the cam (G57) to allow more room by G49 for upward movement of the lever. Found there was a washer under the bolt head (right hand 327) which might have interfered with upshift and removed it.
c) Return springs (G64, G70 and G71) had been replaced with new ones a couple of hundred miles ago and all looked to be in great condition
d) The battery carrier tray is a nice sliding fit with the two slim nuts up against G50. I don't know if that is enough.
e) I drained the gearbox of oil - beautifully clean without evidence of metal fragments, so replaced it via a filter
After all above, I replaced the cover, kickstarter lever, gear selector lever, G81 and readjusted the clutch. I can select all gears, up and down while the engine is off. Started her up and it appeared as if I'd done nothing - same refusal of the selector lever (G78) to even budge in upward direction!
I'm flummoxed, especially since all worked beautifully a couple of months ago.
Post pictures with the kickstart cover off.
It is possible, with care, to operate the gear change without the cover in place. Have you tried that to see whether it is something under that cover which is causing this effect? If you do this and there is no obvious problem then the problem is likely to be inside, rather than outside, the gearbox. Good luck with it.
Do you have Grosset electric start?
Some of the clearances can be very tight.
Some of the clearances can be very tight.
It is possible on some engines, that pending certain clutch adjustments and so on, that the G91 lever can foul the G66 AS lever on the downshift, thus stopping the G 66 from lifting upward for the changing down of gears.........It is merely a matter of altering the clutch adjuster ET27/1AS on the kick start cover, then adjusting the cable adjuster again to gain the proper free play in the handlebar lever........for a stock clutch this amount is usually quite a lot given the mechanism is only lifting one plate.........The 2 E 80 nuts on the battery tray should be done up quite firmly against the G 50 alloy plate so that when the footrest hanger nuts are fully tightened, the G 50 plate does not pull inward at all........the assembly should not be a simple slide in fit, as this will not put enough outward pressure on the G50 plate. This problem usually causes the shift lever assembly to be stiff in its action, but does not usually stop the mechanism from down shifting as you describe.
Greg Brillus - the last name should be Brilliant! He contacted me by email and suggested that the G91 lever might be fouling the selector lever, G66 when the clutch lever is pulled in - and that is exactly what is happening! With engine off, I have been able to downshift because I have not been pulling in the clutch lever, but have needed to do so with the engine running. Thank goodness for an easy fix.
Thank you again, all of you, for your kind suggestions - I have learned from each of you. And a mighty thank you to Greg.
Thank you again, all of you, for your kind suggestions - I have learned from each of you. And a mighty thank you to Greg.
It was a long time ago that this happened to a bike a had worked on.........we were in our old house, so before 2013.......I remember riding the bike around the block on a road test all going well........then I went to slow down and the bike just would not down shift at all.........I could manually shift the gearbox back down the gears via the indicator lever only........Back home it became obvious with the inspection cap removed, you could see the clutch lever hitting the G 66 with the handlebar lever held in........It has only happened to me the once........At the time I thought that perhaps it might have been due to a larger than normal bend in the G91 lever, but I think it was just a combination of the lever and pivot points that may have been the problem........Glad all is well again for you.........Cheers.........Greg.