broken gearbox

[tuske427]

It's a 1999 Yamaha R6 with 27k miles....

Last night while attending bike night my bike stopped working.  All was well when I pulled to the parking lot in Calabassas, but when I went to leave my bike didn't move at all.  No matter what gear I selected, let the clutch out, etc.  nothing.  

even shutting the bike off, the bike rolls freely.   there is no engagement of the geartrain at all.  

There were no clunks, no leaking fluids, no odd noises.   It just stopped working.

I did have a pre-existing "second gear  syndrome". Is this related?  

Not sure if the clutch fork broke?  the clutch itself seems fine, but I could be wrong.

Any suggestions, reccomendations?  anyone out there with an experience like this?  

Thank you for your time!

[Chris_s]

you sure the cable isnt just broken?  it could be numerous things if it not just your cable.  check the simple stuff first.  a clutch dosnt usually stop working unless the cable snaps.  make sure when you pull the lever its is actuating the clutch itself

[tuske427]

HI Chris:

I dont' think it  is the clutch cable.  the clutch lever still has tension and returns to it's original position. Plus, It doens't grind gears when I try to shift with the engine running.

Also, when I move the shifter, the bike should engage gears regardless of the clutch or cable.  it does not.  the bike remains free rolling regardless of where the shifter or what gear its "in".  

when the engine's  off, if I shift it into gear, the bike ceases to be free rolling.  mine is still free rolling.  

the engine is definetely separate from the geartrain.

engine still runs (still have to put it in neutral to start)   when it is running and is in gear, I can hear something spinning inside the gearbox.

Imagine trying to drive your bike with the chain removed.  this is what it's acting like.

Thank you for your suggestion, I do appreciate the reply!

-BV

[Super Dave]

You're not going to fix it by looking at the outside.  

Get someone who knows what they are doing to start by opening up the clutch cover.

You might just want to look to see if there is anything wrong with the counter shaft sprocket.

[tuske427]

I took the bike in- turns out the counter shaft is stripped. (front sprocket came off)  will be a major repair.  

[Super Dave]

Bingo!

[Scott]

Super Dave:

That was almost "Sixth Sense" like....

[tuske427]

What gets me (and maybe this is indicative of a "repair shop" versus "fixing it oneself") is the shop I took it to told me it couldn't be saved. It had to be replaced.  They said that sometimes they can weld the sprocket on but there wasn't enough material on the shaft  left to weld. (this was the ceap way)  plus, they'd have to replace the sprocket and chain.  Meaning big $$ in repairs.

the guy who bought it told me he tapped the shaft and threaded a new nut on, using the existing sprocket and chain.  No welding, no replacement of parts, just a little time and effort and he should be back on the road soon.

I'm actually happy for him that he could fix it so easily.

Now I can go get  that R1 I've always wanted!  (this repair was my excuse to step up to the R1)

[Super Dave]

Super Dave:

That was almost "Sixth Sense" like....

;D

[Super Dave]

What gets me (and maybe this is indicative of a "repair shop" versus "fixing it oneself") is the shop I took it to told me it couldn't be saved. It had to be replaced.  They said that sometimes they can weld the sprocket on but there wasn't enough material on the shaft  left to weld. (this was the ceap way)  plus, they'd have to replace the sprocket and chain.  Meaning big $$ in repairs.

the guy who bought it told me he tapped the shaft and threaded a new nut on, using the existing sprocket and chain.  No welding, no replacement of parts, just a little time and effort and he should be back on the road soon.

I'm actually happy for him that he could fix it so easily.

Now I can go get  that R1 I've always wanted!  (this repair was my excuse to step up to the R1)

The shaft and the sprocket are splined together.  That's probably what's wrecked.

Someone somewhere neglegted the bike and wrecked it.  That's all there is to it.  Weld it?  If the material is gone, nothing would be properly round, so, you'd be set up to have a chain that is tight or loose at any period of time during the front sprocket's revolution because of that loss of proper tolerences.  

The only proper fix is replacing the countershaft and the sprocket and chain...rear sprocket too on a street bike.

Good Luck!

[tuske427]

The spines looked fine.  It was the threads for the nut that would hold the sprocket on that were missing.  But with welding- one can add material on  and build the metal up to hold the sprocket on.  Or, like the guy who bought it- he tapped the remaining shaft and installed a smaller nut.  

[gsxr_rcr]

if the splines are fine than thats not your problem, unless the sprocket fell off the counter shaft.  You will have  to get the counter shaft replaced, I probably can get a used one at the shop down here in Orlando if you need one.  If you weld it you could ruin it,  if only the threads are stripped you could try to re-tap the threads one size smaller and use a nut and washer to keep the sprocket on the splines and you would be back in business.  As for you 2nd gear i just replaced one on my friends bike and it wasnt too bad it took me 4.5 hours to take it out and repair it, and put it back in the frame running down the street. If you want it fixed i can quote you a price, my friend said the local dealer here wanted like 1000.00 bucks, i did it for less than half of that i think.