Have finally got the M20 fully running after a few months off the road. In trying to trace a small "clonk" on left steering lock, I took the front wheel out and noticed that the nut securing the speedo drive was loose.
First question: How tight should that nut be? I've left it just over finger tight, but I wonder if it needs to be very tight or loosish. Any opinions?
Second question: I had two thick washers on the left side which, it seemed, fitted on the spindle inside the fork leg with a single dished nut on the outside. Does anyone know if this is the correct order? Or should there be a thick washer on either end of the spindle? Stupidly, I didn't note where those washers came from (might even have fallen off the Triumph). But there they were during reassembly. Everything seems to fit together okay. But two thick washers?
Third question: could a loose nut against the speedo drive cause that "clunk"? It's hard to be sure yet, but the clunk appears to gone - or at least reduced. However, I did loosen and re-tighten the nut on the steering stem (bearing adjuster nut, I think). So that might account for it. But there's no obvious play at the steering or the wheel bearings. The steering swings freely, but not too freely. No binding. No graunching. Any thoughts?
Hi Danny..the speedo drive box nut should be done up tight. However, you need to check a couple of things before doing that. The drive box dogs that fit into the slots in the hub can bottom out in the slots before the center of the box is resting against the bearing adjustment locknut. If you then tighten up the nut you will squash in the middle of the drive box casting. Usually there is a washer fitted against the bearing adj. locknut (inside the drive box casting) to ensure that the drive dogs don't 'bottom out' when the box is pushed fully home.
As you seem to have a surplus of washers on the outside it may well be that the inner washer has migrated from its correct location against the bearing adj. locknut....Ian
Ian. Fantastic. That explains it perfectly. The reason I was unhappy about tightening the nut against the drive box was because I could see the casing losing shape.
Also, that explains why I didn't notice the two washers. I suspect they came off with the front wheel while I was mucking around on the other side of the bike. I assume that I need to fit one washer inside the drive box and the other outside? Would that be correct? Or is it possible that BOTH washers should be inside the drive box?
One inside the box and one outside the nut is the way I usually fit them...that may not be right as the outside one might belong under the nut, but I feel it is better to have the washer against the back of the forkleg (for a better footprint) than the nut...Ian
Thanks Ian. I'm pretty sure that that was how it was fitted. I remember seeing the nut immediately against the drive box. But it's odd that there's no washer there, isn't it?
Also, could a loose drive box produce that clunking noise I mentioned? It wouldn't have any effect on the bearing pre-load, presumably? That seems to be controlled by the two nuts on the spindle.
Yes Danny..bearing adjustment is taken care of by the nuts inboard of the speedo drive and wouldn't be affected by the speedo drive itself. It is rather interesting actually. I had a similar noise on my M20...when the bars were turned to the left (if I remember correctly) there was a metallic soundng 'click' rather like something was put under pressure and then released. It only happened when the bars were turned one way and I was never able to conclusively find the source of the noise. Possible candidates might be the steering damper assembly, wear in the forks, steering head bearings (though I don't think it was that.) or something else! Does my description match the type of noise you have?...Ian
Hi Ian, yes, that's exactly it. I couldn't find any fault with the steering bearings, or the wheel bearings. However, when I loosened the steering damper assembly, I couldn't hear the click - but I don't know if that was simply because I was taking some load off the head bearings.
Thanks for the advice about the washers. I'll sort that out tomorrow. The clicking noise, whatever it is, doesn't sound serious. Just have to wait until something breaks.
One final point; I keep trying to remind myself when working on bikes not to "blindly" follow directions/instructions, but to try and work out what the designers were trying to achieve. Constantly I lose track of this important point. If I'd thought harder about that, I probably would have worked out where the two thick washers go. Luckily, I can just ask you.