[Camdenp]

I have a 81 Honda CM400C that I’m restoring and the transmission is acting kinda weird. It starts up and I only can feel and tell when I shift down, it makes the clicking noise but when I go to shift up nothing happens. I think it’s the clutch but just want some more insight.

 

[cmonSTART]

Any bad sounds when shifting? While it's always good to make sure your clutch is adjusted correctly the fact that it will shift one direction and not the other makes me suspect a bent or broken shift fork in the trans. Hopefully not, and hopefully someone else will have some other ideas.

When you shift down from neutral to 1st does it grind or does it pop right in? If you start letting out the clutch does it want to move?

I think the C model is a one year only bike - good find!

 

[Camdenp]

No bad noises I can hear and yea the neutral light goes off signaling it’s in first but still stays in neutral and shifting up nothing happens, it feels like the forks are disconnected or just not engaging at all

 

[cmonSTART]

Bummer. They're usually a pain to get to.

 

[Camdenp]

I hope it’s just the clutch plates because the bike has been sitting for years and not the transmission

 

[cmonSTART]

Here's something to try if you haven't already. Centerstand the bike with the engine off and try to shift down into first while turning the rear wheel with your hand. No clutch involved. The movement of the rear wheel should mesh the gears as you shift and you'll feel it engage in the rear wheel. Try the same thing shifting up into second.

 

[WintrSol]

Most bike transmissions have to be moving to shift; when you shift into 1st, the input shaft is still spinning from the clutch driving it until you disengaged it, but then, it stopped moving when the gear engaged. If you shift back to neutral, let the clutch out to spin the input shaft, then disengage the clutch and try 2nd. Or, with the bike on the center stand, the rear wheel spinning should keep the transmission turning, and you should be able to reach all gears.