Noise from transmission/clutch 81 (K)Z1100 A-1.

Hello!
I've owned this bike for over 30 years. It has now close to 200,000 km or 125,000 miles on it.
The engine has been apart twice since I bought it.
Over the last 5-6 years I've noticed a squeking/whining noise coming from the transmission area.
It's present from take off in all gears. I can hear it really good riding at low speeds with a load on the engine/transmission.
At high speeds I'm not sure if it's there because of the wind noise.
When I engage the clutch it goes away.
I have changed the front bevel gear case with a used on with much lower miles on it.
Last winter I split the engine and changed all the bearings in the transmission.
Noise is still there.
Any helps will be greatly appreciated!

Transmission "whines" are often caused by "worn gears" - when you had it apart did you inspect the gear "teeth" for signs of wear or failing of the hardening ? also with the "bevel gears" did you "shim" them to set the backlash ?

I have a similar problem with my Z1.  I am suspecting the oil pump.

I cheked the gears for wear and tear and could not see anything wrong. Did not measure anything.
Have read that because the gears are straight cut the transmission will make a whining noise?
The used front bevel gear case was replaced as a complete unit, and was never taken apart.
According to the seller it came from a bike that had about 30,000 miles on it.
Had the exact same noise before I changed the front bevel gear case.
By the wqy, could the clutch basket cause this kind of noise if it's worn?
When the bike idles in neutral around 1000 rpm I can hear noise that sounds like slack coming from inside the transmission area.
When I engage the clutch it goes away.

You mean the whining is coming from the oil pump?
On my bike I can hear it coming from the transmission when the bike is driven.
When in neutral or the clutch engaged the whine/squek is gone.

janroger64 wrote:

I cheked the gears for wear and tear and could not see anything wrong. Did not measure anything.
Have read that because the gears are straight cut the transmission will make a whining noise? straight cut gears are noisier than helical gears but not to the point you would hear it when riding (IMHO)
The used front bevel gear case was replaced as a complete unit, and was never taken apart.
According to the seller it came from a bike that had about 30,000 miles on it.
Had the exact same noise before I changed the front bevel gear case.

By the wqy, could the clutch basket cause this kind of noise if it's worn?
When the bike idles in neutral around 1000 rpm I can hear noise that sounds like slack coming from inside the transmission area. The chattering at idle could be a worn clutch basket
When I engage the clutch it goes away. Do you mean "disengage" the clutch (when you pull the lever in ?)

I guess at 125k mls everything is going have a degree of wear, have you tried running it in gear on the main stand (you could get a buddy to sit on it and gently apply the rear brake to apply some load) then listen to it with a "mechanics stethoscope" (these are cheap and surprisingly accurate at pinpointing the source of noises) move the probe around the engine to identify the area the noise is coming from which will give you some idea before you "dive in"

Have been thinking about that. Will give it a try. Thanks for the answers! janroger64.

It´s the shaft transmission angle gear play or a bad bearing of it that get noisy.

Just replaced all the bearings in the tranny last winter.
Could you explain some more about your theory? Not sure what you meant.
Thanks! janroger64.
 

Did you shim it to get the correct play?

janroger64 wrote:

You mean the whining is coming from the oil pump?
On my bike I can hear it coming from the transmission when the bike is driven.
When in neutral or the clutch engaged the whine/squek is gone.

Same thing with my Z1.  But I think there needs to be some load on the engine for the whine to occur so I don't hear it in neutral.  I have the bike on my lift and intend to take the engine apart this winter.  I rebuilt it several years ago to get rid of the whine but it was still there.  I replaced the transmission bearings but not the crank bearings.  I also replaced the camshaft rollers.  I figure if it isn't the oil pump then it must be a crank bearing, but they are all good....spin freely and show no pitting.  

hardrockminer wrote:

janroger64 wrote:

You mean the whining is coming from the oil pump?
On my bike I can hear it coming from the transmission when the bike is driven.
When in neutral or the clutch engaged the whine/squek is gone.

Same thing with my Z1.  But I think there needs to be some load on the engine for the whine to occur so I don't hear it in neutral.  I have the bike on my lift and intend to take the engine apart this winter.  I rebuilt it several years ago to get rid of the whine but it was still there.  I replaced the transmission bearings but not the crank bearings.  I also replaced the camshaft rollers.  I figure if it isn't the oil pump then it must be a crank bearing, but they are all good....spin freely and show no pitting.  

Probably worth going over it with a mechanics stethoscope (around $20 on Amazon) before disassembly, you should be able to pin point the area where the noise is coming from before stripping