somthing BROKE, HELP!!

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May 6, 2006
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Cruising along, 4th gear, 65mph, I hear a clanging below. Look down and my kick lever has rotated counterclockwise to the 6 o'clock position. Nursed it home in 4th(no fun!!). The kick lever works to start the bike , but I can only engage 4th gear.PLEASE tell me there is a common simple solution. 2 boys in college, They're KILLING me$$$$$$.
 

L.A.B.

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The kick starter rotating of its own accord (provided that the spring hasn't just broken, and as you can now only get 4th gear it probably isn't that) is a symptom of layshaft drive side bearing failure if it is the old ball type bearing?

If it is that then there could be some damage inside the box?

Do not ride any further until you have investigated the cause of the problem, as the gearbox could lock up solid if it is the layshaft bearing breaking up!!
 
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L.A.B. said:
Do not ride any further until you have investigated the cause of the problem, as the gearbox could lock up solid if it is the layshaft bearing breaking up!!

First rate advice there. These are absolutely classic symptoms and at the very least, continued use is likely to damage the case beyond economical repair as well.

I'm afraid this is a gearbox out job. A good idea to loosen the mainshaft nut before you dismantle the drive side.

If you're lucky, you might just get away with new bearings but check everything. If you're forced into a new cluster then the RGM products are well worth looking at.
 
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Jan 4, 2007
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had the same thing happen.......turned out to be a rebuild. pull the box look everything over carefully. when I pulled the box....first gear was in 3 pieces, just barely hanging together. haven't had a problem since until I broke my kickstart pawl a few weeks ago, but that another story.
I have heard that layshaft bearing failure is hardcore and has even caused a few major accidents.
Eric
 
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I haven't been inside the Commando box but I've done a couple of the singles boxes in situ, don't know if it's possible here? If you're lucky you can pull the bearings without removing the gearbox shell and do it in the bike.
Just a thought before you go pulling the bike apart.
millard
 
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Your layshaft bearing is shot. Cage has likely disintegrated. If you are lucky, like I was, you will hopefully have minimal damage to the case and the gears. Recommended upgrade is to a roller layshaft bearing. It is very difficult to get the broken layshaft bearing race out of the gearbox and get a new bearing installed with the gearbox in the bike. The layshaft bearing sits in a recess in the gearbox case and you can't get behind it to extract it. I would take the gearbox out of the bike to work on it.
 
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I have had this happen, you can do the reapir leaving the gearbox shell in the bike, to get the bearing out you heat the shell and then using a block of wood belt it from the driveside, if the shell is hot enough then it should pop out, it may also have disintergrated enough to drop out anyway. Mine had a few 1/2 balls in the bottom, any of these could have wedged in between the gears to lock the back wheel up.
 
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If you leave the box in situ with sleeve gear and mainshaft, it will not be possible to ensure that there is no swarf in the sleeve gear bearing. If you don't do it, Sod's law says that there will be other problems. If you remove the gearbox internals and then decide to dismantle the primary transmission then it is not as easy to lock it for undoing everything.

With the primary chaincase removed to allow removal of the sleeve gear, it's not a lot more work to then take the shell out.

A roadside or campsite repair can be done without taking the box out but I wouldn't contemplate it if I had the time and facilities to do the job properly. This is a safety critical aspect and should be done to the best of ones' ability.
 
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