'Clunk'when pulling away form neutral.. xj900f 120. K. Km.

Dear everyone,
When pulling away from neutral with my '88 xj900f sometimes there is a 'clunck'. Especially with heavier passenger..
I was suspecting the part in the gearbox where there is a 90 degree angle in the transmission to the final drive, but could it be the clutch?

 

Not the clutch. They all do that it is the middle drive gear damper re engaging parts 4 and 5. When I got my 900f I was concerned about the noise too it is normal. I can hear mine re engaging when I rev the engine in neutral sometimes.

https://images.cmsnl.com/img/partsl...f1-middle-drive-gear_big3IMG00976889_d0ac.gif

 

I understand, But i am looking for the cause of that sound, you can also feel it and it's getting worse..

Loose clutch part or? Broken spring between 4 and 5?

 

If spring 6 was broken chances are the cams on 4 and 5 would be seperating all the time. Can you put the bike in neutral start it and rev the engine see if you can hear the clunk. In the clutch the hub the bearing can wear out but that is a loud screeching sound not a clunk. Only other wear items are the plates and the release bearing so I doubt it is the clutch. If you can make a video upload it to Youtube and post the link here fo all to hear people can give their opinions. I know the cause of the sound is parts 4 and 5 re engaging on my machine but mine does not get worse.

 

https://xjbikes.com/forums/threads/clutch-and-clunk.67651/

 

Thanks for response..
You can not 'imitate' it by hand, it occurs under strain (Me, or me and passenger) waiting at a traffic lighjt and pulling away from neutral. You can heer and feel the 'clunck'.

 

I can make my bike clunk as follows. Put the bike on the centre stand, start the engine in neutral and open then close the throttle. Rev the engine hard and shut the throttle quickly. Try it for a few minutes if need be. Mine clunks sometimes like this when I shut the throttle off. It does not happen all the time hence try it a few minutes. Try it if it does not make a noise then look at the back end of the bike, swinging arm bearings, wheel bearing, flange bolts on driveshaft to crankcase. Unlikely they would cause that. Remove the gear change lever and the cover put it in gear and turn the back wheel by hand see if anything makes a noise. Exhaust pipe header loose, and noise inside clutch cover?

 

I assume there is no problem with the bikes handling?

 

No problem with the bike handling and everything is okay with the frame, wheels and everything. The noise and feel comes from the gearbox, when pulling away from neutral.
I can not imitate or make it clunk an other way. You have to be on the bike giving a load.
Can i remove the left hand cover without problems?

 

Yes drain the oil remove the gear lever, breather hose to airbox and the bolts securing the cover. With the bike on the centre stand you can rotate the back wheel and check for anything loose from the middle drive gear clams and spring. Problem is though they won't seperate and re engage with the engine not running. You can move it up and down the gears too soo if you can get any noise that way. Do you have a Haynes manual for the bike? The bevel gears you see when the cover is off the one facing you parts 4, 5 and 6 are behind that. The four Torx screws holding the securing plate are staked so are unable to slacken off on their own. The output shaft flange is secured to the crankcase with four bolts and shims. If you ever remove these note the position of the two shims they must go back the same way to keep the gear lash right and prevent wear. Just saying you won't have to remove them unless you need to split the crankcase to get to the gearbox internals.

 

Here is how the cover is removed.

 

yes i have the haynes.. Thanks!!