Identifying a rattle or clicking sound when deaccelerating

[Gene]

Had my 2000 Interstate up on rack for maintenance (tires, bearings, pipes, rear drive and all brakes but no engine work). Reassembled and on test ride I get a rattle or clicking sound when letting off the throttle, mostly in 4th and 5th gear at speed but it shows up across all gears. I can't locate it but believe it is toward the front of the bike, but I have ruled out front calipers or wheel track. Any ideas?

Gemini mentions the clutch basket or rear drive could be the cause. I had the drive shaft out for inspection, cleaned and changed oil in the rear differential. I don't think it is coming from there.

Scratching my head on this one. Any suggestions would be greatly appreciated.
Thanks!

[98valk]

the removable side covers on the oem exhaust pipes where the foot pegs are.

[Gene]

Checked those exhaust side covers and they are tight and snug. Thanks.

[Jess from VA]

Sometimes you can locate a rattle by sticking the bike up on the lift and then going around rapping things with a rubber mallet, or shaking the bike.  (although maybe not if only on decel)

I had a rattling noise that was driving me crazy that turned out to be my corded earplugs (half helmet), where the cord was being blown around and tugged on by the wind.  That took a long time to discover, and a lot of rapping and shaking the bike for nothing.   I'd take the plugs out thinking I might better hear where it was coming from, and then nothing. 

Solved with no-cord ear plugs (for hearing conservation). 

[WintrSol]

Is the clicking related to the rpm, i.e.: it is faster at higher rpm?

[Gene]

Thanks for the input!

I don't believe it changes rpm or correlates with engine rpm, but as soon as this weather lifts I'm going to give it another test ride. That said, I believe I was able to affect the rattle with the clutch, but I'm going to collect more data on that on my next ride. Will get back shortly on this issue.

[WintrSol]

Also, give a close look at the clearance between the front calipers and moving wheel parts. The slight shift in weight could change a close pass to a light touch.

[Gene]

Yeah, my front left caliper needed a lot of adjusting to get it to clear the moving wheel studs. There is clearance now, but not much, and much less than the right caliper. Its clears nicely on the stand, but not sure how much it shifts when deaccelerating. I can't seem to adjust that clearance any more. The wheel studs are actually too close to the fork mount, maybe 2mm.  Not sure how that can be adjusted unless the wheel spacing is off. If it moves under deacceleration that could be the culprit.

Still researching this.

[WintrSol]

Look at the diagram at the bottom of page 13-15 in the FSM; clearance stated there. The fork has to be in the correct position on the axle before tightening the pinch bolts, so the clearance meets spec.

For reference, my axle is just slightly above the surface of the fork, where the curve of the fork meets the axle at its highest point. I've read that some axles are marked with a reference line, but it isn't mentioned in the manual.

[Chrisj CMA]

Post a picture of the end of the axle (clutch side). Let’s see how flush it is with the fork lower

[WintrSol]

Post a picture of the end of the axle (clutch side). Let’s see how flush it is with the fork lower

Gene, or me?

[98valk]

Checked those exhaust side covers and they are tight and snug. Thanks.

however the interlocking tabs could have lost their rubber covers and I have found even if they are there the cover could still be installed where it is slightly distorted and vibrates against the pipes.

[Chrisj CMA]

Post a picture of the end of the axle (clutch side). Let’s see how flush it is with the fork lower

Gene, or me?

The clicking could be a mis-aligned left fork

[WintrSol]

The clicking could be a mis-aligned left fork

Yes, and the procedure on FSM page 13-15 should take care of that.

My axle position, left fork:

[Rio Wil]

It seems most axles have a tiny groove cut in the big diameter of the shaft. Align the tube so the groove is just visible on the inside edge of the tube.

[Hook#3287]

Have you inspected the u-joint?

Because you stated you hear the click on deceleration, I'm thinking that could be the issue.

It would be timed with speed and not rpms.

The one time I reinstalled a front axle incorrectly, the clicking was heard right away and not just on decel, but anything could happen.

[Chrisj CMA]

The clicking could be a mis-aligned left fork

Yes, and the procedure on FSM page 13-15 should take care of that.

My axle position, left fork:

Loosen those pinch bolts and move the fork out until flush with axle head

[Chrisj CMA]

Yeah, my front left caliper needed a lot of adjusting to get it to clear the moving wheel studs. There is clearance now, but not much, and much less than the right caliper. Its clears nicely on the stand, but not sure how much it shifts when deaccelerating. I can't seem to adjust that clearance any more. The wheel studs are actually too close to the fork mount, maybe 2mm.  Not sure how that can be adjusted unless the wheel spacing is off. If it moves under deacceleration that could be the culprit.

Still researching this.

Adjustment is made by moving the left fork out to where it’s flush with the head of the axle

[WintrSol]

Loosen those pinch bolts and move the fork out until flush with axle head

It's been a while, but I think I recall having the reference line on the axle, and I lined it up there. No issues with clearance.

[pancho]

You said rattle or clicking, so this may not apply. But if you have a clunk when decelerating, that can come from u-joint or spring loaded drive line.

[Gene]

Weather just cleared enough to get the valk back out on the road to research this rattle. I'm convinced it is not the front wheel now and the rattle is more of a gear grind. I had the rear disassembled for new rubber and brakes. Since I had the stacks off I decided to clean up the rear universal and I had the drive shaft out. I suspect the drive shaft now, but when I reassembled it it seems to slip right in on the splines and the universal fit just right. I didn't do anything to the drive shaft but inspect it, clean it and lubed it before reassembling.

The rear drive train is the only thing I touched during my maintenance, so now I suspect I may have done something wrong on that reassembly, but am scratching my head on what it might be.

I'm going to jack the bike up this weekend and disassembling to get to the drive shaft. But I'm not sure what I'm looking for, or to do in reassembly except what I just did. Checked the FSM for some tips, but I didn't see anything there that I may have missed.

Anyone have any suggestions?

[Gene]

One more thing I noticed in my test ride. I never hear the gear grind on acceleration or under power, more when I pull in the clutch, or deaccelerate. 

All five gears shift fine, no slipping or grinding when shifting. I feel like it may be the driveshaft connection on the engine side, but I'm not sure. The sound seems like it is there, but hard to pinpoint. It is not the universal on the rear wheel.  Its more forward that that.

[Skinhead]

Did you check your rear bearings?

[Chrisj CMA]

One more thing I noticed in my test ride. I never hear the gear grind on acceleration or under power, more when I pull in the clutch, or deaccelerate. 

All five gears shift fine, no slipping or grinding when shifting. I feel like it may be the driveshaft connection on the engine side, but I'm not sure. The sound seems like it is there, but hard to pinpoint. It is not the universal on the rear wheel.  Its more forward that that.

Go ahead and pull the drive train including the U-joint which is on the engine side of the drive shaft. Then you’ll know one way or the another

[John97]

Please correct me if I’m wrong but checking a ujoint by hand only does so much right? Like you can feel a notchy feeling or a roughness moving it around at every possible angle but don’t you have to use a breaker bar with the joint secured in a vise to find any possible movement that would only be felt installed with the weight and force of the bike against it?

[Timbo1]

Please correct me if I’m wrong but checking a ujoint by hand only does so much right? Like you can feel a notchy feeling or a roughness moving it around at every possible angle but don’t you have to use a breaker bar with the joint secured in a vise to find any possible movement that would only be felt installed with the weight and force of the bike against it?

Probably depends on how it went bad.   I had one go bad and the only symptom I had was slight vibration on deceleration.   But it was easy to diagnose because I could easily see that one of the caps was broken simply by pulling the boot back and looking at it as I rotated the rear wheel back and forth.   I guess if it's not broken like mine or have had the needles fall  out yet it would be more difficult to identify while still on the bike.

[Chrisj CMA]

Please correct me if I’m wrong but checking a ujoint by hand only does so much right? Like you can feel a notchy feeling or a roughness moving it around at every possible angle but don’t you have to use a breaker bar with the joint secured in a vise to find any possible movement that would only be felt installed with the weight and force of the bike against it?

Probably depends on how it went bad.   I had one go bad and the only symptom I had was slight vibration on deceleration.   But it was easy to diagnose because I could easily see that one of the caps was broken simply by pulling the boot back and looking at it as I rotated the rear wheel back and forth.   I guess if it's not broken like mine or have had the needles fall  out yet it would be more difficult to identify while still on the bike.

If the ujoint is bad enough to be making his noise it will be obvious.