I may have made a huge mistake (I appear to only have three gears)

[ElFuegoBlanco]

I'm in the final stages of reinstalling the motor on a RD400c.

When I press the gear selector all the way down, the neutral light comes on. There's no more going down from there. Lifting the selector, I get only three clicks before there's nothing else left.

Give it to me straight. Did I reassemble the gears backward or something foolish along those lines?

Rob

[ElFuegoBlanco]

After a short drive to cool off a bit, I took another look.

It actually will cycle through all the gears if I wiggle the final drive sprocket. In many cases, there's almost like a false neutral between gears where the final drive sprocket will spin freely. If I press down slightly on the shifter and then firmly up, it will go to the next gear. Hopefully this isn't a sign of a worn transmission.

[Striker1423]

Misassembly is the likely cause. Why? Because I did it and felt like an idiot.

Same symptoms. Neutral all the way down and onto 2 or 3 gears. Trans would lock. You have one of the dogs backwards is my guess.

[1976RD400C]

Before you panic, try shifting through the gears while actually rotating the drive sprocket with every shift. That is a must to get it to click firmly and all the way into each gear.

[ElFuegoBlanco]

Before you panic, try shifting through the gears while actually rotating the drive sprocket with every shift. That is a must to get it to click firmly and all the way into each gear.

After calming down, I ran through the gears about 2 dozen times, applying pressure to the sprocket and it looks like all is good now. Thanks for the advice!

On to the next crisis, I guess.

Rob

[Diablo007]

I had a similar problem with an RD350 transmission.  I had assembled the shafts by looking at the parts diagram as was unable to run through all the gears.  As I had not closed up the cases I watched as I ran through the gears and realized that I may have put a gear in backwards.  Switched the gear around and, 'voila', I had all the gears working.  A friend emailed me the page in the service manual that shows the transmission after I had emailed for advice.  I had looked at it while trying to sort out the problem but apparently not close enough.  The manual shows the gear in the correct orientation, the parts diagram apparently does not.

Crazy all the errors I'm finding.  My friend who was a Yamaha dealer from '68 through the late '70's says it's because the factory did not have the manuals proofed by a native English speaker.  Though that doesn't explain this particular error as the manual was correct.  I'm guessing the orientation was changed in the parts diagram for clarity of the gear dimensions.

[ElFuegoBlanco]

I think I'm good to go. Just had to work through the gears a bunch of times.

I'm fortunate that I took decent pictures during the disassembly and that I have a 'spare' transmission to refer to. That's why I was in disbelief that I may have assembled it backwards.

[m in sc]

its fine, the rd transmissions are surprisingly durable. but as stated, you have to roll the input or output to get the dogs to align. i always swath the parts in oil before i assemble.   Typically, as long as neutral is fine, the rest lines up.

kawi triple transmissions however are a real pia, shims and aligning pins. whats a recipe for disaster if you get it wrong.