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Discussion Starter · #1 · (Edited)
First off, im new to motorcycles and auto repair in general but i want to be more knowledgeable and start doing repairs on my own. So any advice would be greatly appreciated. I started noticing a whining noise coming from the crank case or more or so where the transmission is of my 1974 CB360. When its in neutral its really whining fast but when i change it to first gear it stops until i start moving then the whining noise slowly starts building up and gets faster as i add more throttle. I looked online and the only information i gather was that the bearings on the transmission are damage. Can anyone give me some insight on what other causes it might be. Or any preparation for fixing these bearings? thanks. note i also thought it was the cam chain so i already adjusted that and that didnt seem to do the trick.
 

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Welcome - but if your model of bike isn't in your profile or in your post, it will be difficult for people here to help.
 

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My bike used to whine when I would coast in neutral and I found that my clutch adjustment was just wrong. Could be that your clutch is slightly engaged when it shouldn't be and causing the noise. Worth a shot.
 

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Discussion Starter · #5 ·
My clutch cable did snap off the hinge about a month and a half ago as shown on the picture (1). I tried fixing it my self but whenever i put back together it wasn't getting any traction when i change it into gear. I took it to a shop and they re-adjusted the clutch and told me i placed the bearings (picture 2) wrong. They fixed it but maybe something happened. That might be it so ill check. Thanks. Auto part Engine Automotive engine part Carburetor Transmission part
 

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Other thought - I’d check the mating surface of your oil slinger where it meets the output on the cover. If the cover gasket was replaced with one thinner than stock, it can press them together too hard and that metal on metal contact can produce a whining/squealing noise that varies with RPM. Ask me how I know :D
 

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In other words, when the input shaft and the clutch center are turning it makes noise. When in gear, the input shaft and clutch center stop the noise stops. It would help to know if the noise changes in pitch or volume in different gears. It could be a bad bearing on the input shaft, but it's very unlikely,given the size and capacity of the bearings used. You might check the clutch adjustment, on the oft chance that the clutch lifter adjustment is too too tight(not backed off for running clearance) and the clutch pushrod is running against the pressure plate all the time. A damaged gear on one of the shafts would make more of a rattling noise and would be more pronounced in one gear that the others.
 

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I’m very sorry Mike in Idaho. This is a five year old thread, but I just couldn’t resist adding my pointless joke. I did not mean to accidentally waste your time by bumping it into activity.
 

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Oh well, I needed something to do , while I had My coffee this morning, anyway.
 

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I can recall two issues that caused a sort of whining sound to come from the bottom end of a cb350 race bike. Both examples will cause symptoms that very nearly match what you describe.
1: One of the clutch bolts backed out on me once. When that happens, the bolt bounces around and head makes intermittent contact with the side cover. Both get worn down increasing the gap between the two. Whining sound is obnoxious one minute gone the next, like an angry bee is trapped inside it. I cannot recall this impacting the performance of the clutch. Replaced the bolt Loctite'd the crap out of it.
2: The later type kickstarter which is pretty much the same as on a 360 motor has a ratchet mechanism with teeth or dogs oriented so that the pinion is grabbed and pulled in to engage as you rotate the lever... if the motor fires it begins to spin the shaft faster and now those teeth push the pinion away to disengage the two BUT only barely enough. Afterwards a spring takes over and pushes that kickstart pinion well clear. Well, when the ratchet teeth and that spring wear down over time.... you end up with a pinion that makes intermittent contact with the ratchet teeth. Revving would "sometimes" cause this sound to go away for a minute or so. I remember that I could feel a very slight vibration with my finger while touching the kicker spindle.

Get yourself a mechanic stethoscope and start poking around while the motor idles. This is also good and fun with a perfectly healthy motor.
 

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In other words, when the input shaft and the clutch center are turning it makes noise. When in gear, the input shaft and clutch center stop the noise stops. It would help to know if the noise changes in pitch or volume in different gears. It could be a bad bearing on the input shaft, but it's very unlikely,given the size and capacity of the bearings used. You might check the clutch adjustment, on the oft chance that the clutch lifter adjustment is too too tight(not backed off for running clearance) and the clutch pushrod is running against the pressure plate all the time. A damaged gear on one of the shafts would make more of a rattling noise and would be more pronounced in one gear that the others.
A whine or a hum is a rattling noise that happens very quickly... like when teeth on gears are interfering when they should not.
 
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