Commando shifting problems

This could bethe return spring in the outer cover, which fails to return the selector mechanism after each shift. It is fairly easily changed just by removing the outer cover, and the spring itself is also widely available. The camplate index plunger could also be the culprit, with either a weak spring or the plunger itself being rounded and unable to lock the camplate. A very good place to look this up and order spares at the same time is www.andover-norton.co.uk , who has a very informative webshop with exploded diagrams of the entire motorcycle, including the gearbox.

Hi. I may have misunderstood you, but are you using the clutch each time you change gear? Norton boxes require the clutch to be pulled-in before changing gear - they're not like modern bikes!

If you have a standard 71 Commando the gears should be one up three down, so to change up the pedal needs to be depressed and vice versa. Unless of course you have a reversed lever (rearsets?) or a reversed camplate. If the clutch is dragging you will also experience difficulty with a clean gearchange. You should be able to make reasonably good upward gearchanges without the clutch if you back the throttle off as you make the selection. going down the box is a little more difficult and not to be tried on someone elses bike.

By the way, is there any oil in the gearbox?

Inspired by David Evan's reply, it may be a clue that the problem has gone from bad to worse, and especially last night. This gives me backflashes to a clutch center nut coming loose, or an adjuster screw doing the same. But this would be indicated by the clutch lever coming closer and closer to the handlebar before activating the clutch. Don't ask me how I know this !!!

Tom, Nought out of ten for use of the apostrophe, Dave Evans's reply I think is correct. Don't ask me how I know this

Having just stripped my Commando I found the clutch centre nut loose, though retained by the tab washer. I'll be using Loctite when it all goes back. At the current rate of progress probably about 2013

Sorry David, a slip of keyboard me thinks! On my first restoration, a Matchless G80, I got 40 miles away from home, when the clutch lever moved closer and closer to the handlebars. Suddenly very frightening noises soundedfrom the primary drive, and then no propulsion! Miraculously nothing else was destroyed in the primary, and I was able to fit the clutch back on the gearbox axle and continue. Back home I checked it again, and since then Loctite has been used on this particular nut, and no probs since!

Clutch centre nut loose eh? I remember having that problem with an ES2. I always smack the clutch centre nut on with an air impact spanner these days, that seems to do the trick. It is hard to hold everything steady when trying with conventional tools.

The problem on the Commando is the nut is being locked up to 70 ft/lbs against a puny little circlip. Someone else on the forum suggested about 40ft/lbs and I'm inclined to agree. Loctite seems to be the way ahead.

Previously wrote:

The problem on the Commando is the nut is being locked up to 70 ft/lbs against a puny little circlip. Someone else on the forum suggested about 40ft/lbs and I'm inclined to agree. Loctite seems to be the way ahead.

Interesting, seems like my Commando has been modified in this area. The clutch basket rests on a heavy3-4mm wide spacer/washer, which again rests on the splines of the output shaft. Looks pretty solid to me, but ofcourseit only shifts the weak point to the end of the splines. Again this mod may be due to a belt drive being fitted, which btw. works really well and makes the whole primary case a nice and dry place

Previously wrote:

I just took my fathers 71 750cc commando out today, and it it having problems shifting from 2-3 and 3-4th gear. It will shift ok from 2nd to 3rd if i apply a slight upward pressure on theshifterand quicklydisengagethe cluch and reengage it. I believe the problem to be a shift fork or something, but i do not know as i have never been in a amc gearbox before.

I had a simalar problem with my 71 commando found the gear change pawl worn, fitted a replacment job sorted.

Tom wrote, "it may be a clue that the problem has gone from bad to worse, and especially last night."

If the problem gets noticeably worse during a journey, my money is on a clutch problem. Anything that causes slight drag can affect the ease of gear changing.