Gear mechanism help needed

Hi all,

I'm really struggling with the gear change mechanism (Kit 22). So would really appreciate any advice. I just can't get the 1st gear yoke to slide easily. it goes tight on the rod. I've been trying to ease the hole that the rod goes though by using emery cloth. it now if anything seems too loose in the rod when it's not in position on the gear. Bit it jams up when on the gear. I'm getting really frustrated with it and am not sure where to go with it now. Has anyone else had this?

Thanks
Ian

Check the selector arm is square to the rod it slides on, if it requires adjustment you can gently grip the U section of the selector arm in a vice and using the rod in the boss flex it to be square, don't overdo it and bend the rod as this will not improve things, if you don't have a vice use the gear on its shaft to hold the selector arm as you flex it, once again don't get to enthusiastic.

It may be the position of the U in the selector arm where it fits around the gear, first remove the rod the arm slides on, fit the selector arm onto the gear and place it in its approximate position, slide the rod back into the gear housing and examine how it fits into the selector arm, you can remove material from the front or rear of the U until the hole in the selector arm lines up with the rod.

Many thanks Ian. That gives me some things to check. I'll let you know how I get on.

I've got it not too bad now.

Following Ian's advice I got it so I could move the gears with the selector arms assembled on the rod. But I had to move them by push the gears themselves If I tried to do it with the lever it would still jam up. I then tried moving the gears by the selector arms without the rod in place and they still jammed up.

So I figured the problem must be with how the gears slide on the splined end of the crankshaft. So I re-read Steve's instructions about how he gears should slide if just pushed from the top of the gear (I missed that bit when I first read it). I found that they did rather catch if just pushed from the top rather than holding the whole gear. So I filed more of a chamfer on the corners between the bores and the faces of the gears. This really improved matters and I could just about move the gears from the selector arms. But they still caught a bit.

I then realised something I should have paid attention to earlier in the build. There is rather deep turning marks on the shaft. I wish I had polished it smooth before Locktiting the keys on. to try and remedy this, I put some fine lapping abrasive powder on the end of the crankshaft and kept sliding one of the gears up and down it for about 15 minutes. After cleaning it of the gears will now move with the lever on the selector arms. It's a bit tighter that I would like but hopefully it will free up with use.

Cheers
Ian

what I have done for years now is put a bit of brasso on the splines and slide the gears up and down the splines for 5 or 10 mins
this takes all the edges of
hope this helps mark

Thanks Mark, Brasso worked a treat. I polished the bores in the gears and where the rod passes through the selector arms and used a mini rotary tool to polish the splined bit of the crankshaft. The gears now slide fairly easily. I'm quite satisfied with how it moves now.

Another question now - Sorry!. The ISO does not very clearly show how the Gear Change Lock goes. Could someone explains it's position and function please.

Thanks
Ian

IanR wrote:Thanks Mark, Brasso worked a treat. I polished the bores in the gears and where the rod passes through the selector arms and used a mini rotary tool to polish the splined bit of the crankshaft. The gears now slide fairly easily. I'm quite satisfied with how it moves now.

Another question now - Sorry!. The ISO does not very clearly show how the Gear Change Lock goes. Could someone explains it's position and function please.

Thanks
Ian

Examine ISO 222A and note the orientation of the lock (seen below the gear lever) in that position one arm of the lock holds the right hand selector in position whilst allowing the left hand selector to slide to the right just missing the other arm of the gear lock, you may need to shorten the forward arm of the gear lock to achieve this position.
The gear lock pivots on the countersunk screw.
pulling the right hand arm of the gear lock backwards swings the left hand side forward, in that position it holds the left hand selector in position whilst allowing the right hand selector to slide to the left just missing the other arm of the gear lock, once again you may need to shorten the forward arm of the gear lock to achieve this position
This prevents you selecting both hi and low gear simultaneously and locking the whole assembly up.

Thanks Ian. I've been out all day so handy had a chance to look at it. Will let you know how I get on.