Whilst riding my 67 Bonneville last Wednesday I realized I had lost first gear. I don't mean crunching or difficulty engaging first gear. It simply felt like it wasn't there. Pressing down the gear lever just met with a solid feel. I got home ok as all other gears were fine and there is a neutral between 2nd and 3rd. I was a little depressed this might mean a complete gearbox strip. Not a pleasant thought.
I removed the outer gear cover hoping it was something in that section. One point here before I continue. I did read somewhere that the outer case can be in poor condition inside as it does not contain oil and can be rusty etc. This is certainly not the case with my bike so either this an incorrect statement or it refers to a different gearbox, a pre-unit maybe? Anyway, after removing the cover I discovered that the upper quadrant return spring was actually broken. There are two springs and they are supposed to act equally against each other to always centralise the gear lever after changing gear. As this meant the gear lever internal mechanism wasn't fully centralising it was stopping one of the quadrant plungers from engaging in order to shift into first. If you have worked on these boxes you will know exactly what I mean. If like me you haven't it took a while to work it all out. I am sure I can't be the only 650 unit rider this has happened to and just in case it should happen to you in the future then don't panic as its a relatively easy and cheap fix. Obviously replace both springs at the same time to maintain equal tension and reliability. Have to be impressed with Triumph for the design of these gearboxes. They appear complicated at first but are in fact incredibly simple and normally robust and the broken spring has no doubt being doing its vital function since 1967. All for now until the next maintenance issue.
I removed the outer gear cover hoping it was something in that section. One point here before I continue. I did read somewhere that the outer case can be in poor condition inside as it does not contain oil and can be rusty etc. This is certainly not the case with my bike so either this an incorrect statement or it refers to a different gearbox, a pre-unit maybe? Anyway, after removing the cover I discovered that the upper quadrant return spring was actually broken. There are two springs and they are supposed to act equally against each other to always centralise the gear lever after changing gear. As this meant the gear lever internal mechanism wasn't fully centralising it was stopping one of the quadrant plungers from engaging in order to shift into first. If you have worked on these boxes you will know exactly what I mean. If like me you haven't it took a while to work it all out. I am sure I can't be the only 650 unit rider this has happened to and just in case it should happen to you in the future then don't panic as its a relatively easy and cheap fix. Obviously replace both springs at the same time to maintain equal tension and reliability. Have to be impressed with Triumph for the design of these gearboxes. They appear complicated at first but are in fact incredibly simple and normally robust and the broken spring has no doubt being doing its vital function since 1967. All for now until the next maintenance issue.