Topic: Transmission knock

[b82ta]

So, I'm getting closer to getting my '77 750 on the road, but I noticed today while pushing it around, there is a knock in neutral....  It makes the same noise when its up on the centerstand and I roll the wheel. It is different from any chain noise, and seems to be coming from the transmission.  Any thoughts on what this could be? It also does only seem to be present in neutral.  If I put it in gear and pull in the clutch and roll it the noise goes away.

[Industrial Cafe]

is it a timed knock or random sounding?

[b82ta]

for the most part its consistent.

[Industrial Cafe]

hmmm....
could be a bearing, I've had a motor where the outer counter shaft bearing was replaced for one reason or another..
do you feel anything in the movement, like something catching, when you hear the clunk?

[b82ta]

It doesn't feel like anything catches, if it does its not much at all.  I think its strange that it only does it in neutral though...

[Industrial Cafe]

could be the dogs on the gears touching, from a worn shift fork.

try lifting and lowering the shift lever, while spinning the wheel and see if it goes away.

[b82ta]

Seems to make no difference.  I did notice that he noise is much less pronounced when rolling the wheel backwards.

[Industrial Cafe]

well, I'm out of ideas, without being there doing it myself.

hope someone has some idea.
good luck

[b82ta]

Thanks a lot.  I am afraid that its something like a bearing on its way out :S  So close to getting this thing done..... ugh

[b82ta]

problem solved?

So I took the sprocket cover and front sprocket off, and spun the shaft, no knock.... so i just put everything back together, exactly as it was and voila no knock.  Now I'm really confused about what the noise was... Could something have been on the sprocket and hitting the case?  I really have no idea...

[Industrial Cafe]

might have been the safety link hitting the cover. mine did that.

so I put it in backwards.

[Tower]

Sounds like you've narrowed the problem down to the final shaft bearing, oil guide, sprocket or chain.  Probably chain or sprocket loosening up.

FYI...
When the engine is running (Engine is driving)
With the clutch engaged: crankshaft is driving the mainshaft,
...and in neutral: the mainshaft is not driving the counter shaft.
...and in gear: the mainshaft is driving the counter shaft and final shaft
With the clutch disengaged: crank is not driving the mainshaft,
...and in neutral: the mainshaft is not driving the counter shaft,
...and in gear: the mainshaft is driving the counterhsft and final shaft

When engine is not running (Rear Wheel is driving)
Chain is driving the final shaft, final shaft is driving the counter shaft
And in neutral: coutershaft is not driving the mainshaft
...with clutch engaged: mainshaft is driving crankshaft (not moving)
...with clutch disengaged: mainshaft is not driving crankshaft
And in gear: countershaft is driving the mainshaft
...with clutch engaged: mainshaft is driving crankshaft
...with clutch disengaged: mainshaft is not driving crankshaft