First time going deep – Gear Box.

grandpaul

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I just tore everything out of my gearbox, replaced the old stuff and threw it back together. Hope I don't blow up on the highway.
While I do cursory checks, that's pretty much what I've done on almost 20 Norton transmissions with 100% success.
 
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Geez... This is VERY thorough.
I just tore everything out of my gearbox, replaced the old stuff and threw it back together. Hope I don't blow up on the highway.
As long as your fuel line's the right colour, you'll be okay...
 

NickZ

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Geez... This is VERY thorough.
I just tore everything out of my gearbox, replaced the old stuff and threw it back together. Hope I don't blow up on the highway.
Maybe I am being overly thorough, and it is taking me a lot longer to finish the gearbox than I thought it would. There is quite a spectrum of folks on this forum. From rocket scientists who race to guys who never worked on bikes before. The advice and recommendations come from across that spectrum. I didn't have any thought of checking shaft deflection till someone asked about it here. I'm not being paid by the hour and I have my other bike to ride, so I figured what the heck. Now I know how to measure shaft deflection.
I probably shouldn't mention that I also magnafluxed the shafts looking for other defects.
 

NPeteN

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Maybe I am being overly thorough, and it is taking me a lot longer to finish the gearbox than I thought it would. There is quite a spectrum of folks on this forum. From rocket scientists who race to guys who never worked on bikes before. The advice and recommendations come from across that spectrum. I didn't have any thought of checking shaft deflection till someone asked about it here. I'm not being paid by the hour and I have my other bike to ride, so I figured what the heck. Now I know how to measure shaft deflection.
I probably shouldn't mention that I also magnafluxed the shafts looking for other defects.
Well said! And if you've got the tools to be thorough you are well served to be!
 

NickZ

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Ok, going for the Dumb Ass award here.
Had to take most of it out of the gearbox shell again because I had to remove the main shaft so I could get a socket on the gearbox sprocket nut. Of course the Workshop Manual told me to do that right after installing the sleeve gear in section D9, but I thought I would wait on that till I had the rear hub back on, never thinking that there was a reason the manual put that step there.
2nd Dumb Ass achievement was self inflicted. I thought I would be efficient and leave the stator connected to the inner chain case by the seal for the alternator wires. It looked like it was sealed nicely and I chose not to undo it. What I didn't realize was how brittle the insulation had become on that wire and it broke so there was no support where the wires go into the potting material on the stator. With all the moving around with cleaning the case etc, the wires were twisted up and broken. I don't know if that can be repaired. Luckily I have a spare alternator laying around so this wont hold me up. I may try to repair the wiring on the old stator at some later time. I'll attach a photo and maybe someone will tell me that would be a waste of time.

Also of note, some DA other than me had installed the stator opposite way. It was installed such that the wires came out of the stator toward the engine. Bike ran ok though. Maybe no adverse consequences for that.
 

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NickZ

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I need help with this one:

I have everything back in the gearbox shell. Installed the inner cover, torqued 7 nuts to 10 ft-lb. Measure 0.005" end play on lay shaft. I take it through the gears and it goes up and down fine. When in neutral the mainshaft and drive sprocket both turn independently and easily. All seems good so far.
I tighten the gearbox mainshaft nut to 40 ft-lb , and now everything is pretty much locked up. The mainshaft and sleeve gear won't turn independently and can't change gears. I notice that the space between the clutch locating circlip and end of the sleeve gear has been reduced from around 0.155" to 0.100".

I have done 3 iterations of taking inner cover off and inspecting etc. Same result each time. As soon as I loosen the mainshaft nut, all good again.

The things that have changed since it was working:
New sleeve gear bearing, bushes & oil seal,
new lay shaft roller bearing,
new 2nd main bush,
New first gear set, main & lay shaft,
new kickstart shaft bushes,
added 0.035" of shim on kickstart shaft to reduce end play,
new pawl plate on back of inner cover,
new inner cover mainshaft bearing,
new inner cover gasket.

It seems that torqueing the mainshaft nut is causing something to bind, but how do I identify what it is? I measured the new 1st main to be 0.002" longer that the one I took out. Would that be enough to cause this problem?

I will greatly appreciate any help or advice.
 

NickZ

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By asking that last question I realized that I can answer it myself. So I substituted the old 1st main gear back in and the problem goes away.
My solution would be to take 0.002" off the shoulder of the new 1st main gear.
Am I missing anything here? Would there be any other consequences in doing that? It seems to be like a puzzle where you change 1 thing and another thing pops up elsewhere.
 

grandpaul

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Do you have a gasket between the case & the inner cover?

If yes, use a thicker gasket.

If no, install one.
 
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