Chatter in 4th gear

[Oss]

I went on search before posting this as Lacon had what seems close to what I am experiencing

In 4th gear when I let off the throttle I heard a chatter like a rattling almost of gears that went away when I gave gas or maybe the exhaust drowned it out?

I did not feel this in 1st 2nd or 3rd and I put it through some hard acceleration today and wearing my half helmet to try to isolate the sound  I was not on roads condusive to 5th gear riding as the speed limit is 40 and the police were out and about

During the week I will try to go out with the go pro in the tankbag and see what the noise sounds like from lower, maybe even try in the saddlebag as well.

About 8ooo miles ago the rear was serviced by me under the watchful eyes of HB and LD and they made sure I had proper alignment and moly where it should be and the drive shaft was also inspected.

I  am wondering if the dampers alone (Have 81000 on my interstate) could do this or if like Lacon I have a ujoint ready to blow. Fortunately I do have a NEW ujoint in my left saddlebag just in case

Has this been covered in another thread that I missed. Sure wish a great Valk mechanic lived nearby

[Michvalk]

I would believe the U-joint is going bad. I can't see the dampers making a chattering noise. No way to be sure unless the joint gives out, or inspect everything again. I would use inspection, as I hate being broke down on the side of the road

[salty1]

It could be a u-joint. I'm going to watch this string and see how this plays out. 

[Oss]

sorry for the dumb question but why would a ujoint only make noise in 4th

I am not pushing the bike hard in that gear, well not as much as when accelerating

[HayHauler]

Can you feel the vibration in your foot pegs?  When mine was making noise, I could feel it in the foot pegs.  I only felt it when letting off of the gas and before the engine drag or coasting happened.  The time in the drive line when you are neither accelerating or coasting, right between these two.  It was a vibration I felt in my foot pegs.

I hope you figure it out before your trip in April.

Hay  
Jimmyt

[Gavin_Sons]

Mine did the same as yours oss. Replaced the u joint at 30000 miles. Could feel it thumping in the highway pegs only in high gear on slack driveline and hear a little noise. Changed it out this past fall and no more noise or thumping. The old one was a little sticky in one plane. Good luck.

[Michvalk]

sorry for the dumb question but why would a ujoint only make noise in 4th

I am not pushing the bike hard in that gear, well not as much as when accelerating

No rhyme or reason. They all have a different sound for some reason. But, when they go out, the riders all make the same sound "OH, SH@$"

[Gryphon Rider]

sorry for the dumb question but why would a ujoint only make noise in 4th

I am not pushing the bike hard in that gear, well not as much as when accelerating

Just like anything that spins that is slightly unbalanced, there will be certain RPMs at which the vibration will become pronounced. It's only in fourth gear that you get the shaft spinning cast enough for centrifugal force (or is it centripetal?) to work against a slight looseness enough to move the shaft off the centre of rotation and cause the vibration.

[sandy]

As for vibration happening in limited gear, speeds: when the joint has a load, the slack is removed. You feel the vibration when the joint is allowed to shake (no load). At 81K, I'd change the U joint.

[PhredValk]

U-joints and bearings will do that when they are starting to go (my Windstar is making that kind of noise now, and I'm pretty sure it's the front right wheel bearing). No noise or vibration when there's pressure on them, just when they are running slack; little or no power or braking applied. I would pull the rear wheel and check the joint and bearings.

Better now than on the road. My buddy Donald was experiencing some noise and vibration from the rear of his Valk and as it happens his left rear bearing grenaded 100 yards from home.
Fred.

[NJF6Cowboy]

Oss,

Give me a call regarding working on your electrical fuse panel and your final drive issues. I would be glad to help you out. Nine seven three six seven zero four one three five.

Stan

[stude31]

Can you feel the vibration in your foot pegs?  When mine was making noise, I could feel it in the foot pegs.  I only felt it when letting off of the gas and before the engine drag or coasting happened.  The time in the drive line when you are neither accelerating or coasting, right between these two.  It was a vibration I felt in my foot pegs.

I hope you figure it out before your trip in April.

Hay  
Jimmyt

Have to agree with Jimmy, I had the same symptoms.

Keep us posted Oss.  I'm curious as to what it is.

Best of luck my friend!

[Oss]

I know many of you dont go on the general board so I want to thank
NJF6COWBOY (Stan) for coming over Saturday.

It was indeed the U Joint and it was ready to grenade on me

Thank you Stan for showing me (again HB and LD let me do one a few years back ) the correct way to do a spline lube
(I had the orings and u joint in hand) and thanks Chrisj for the link to the rattlebars
method of removing the ujoint which we did not use as according to Stan there was lots
of metal shavings in the swing arm. 

Stan is a great fellow and I just want everyone to know     

[salty1]

ATTA BOY Stan!!!    Glad to hear you got it dealt with Oss.    Very interesting thread.

[fudgie]

Ujoint. Hollywoods bike did the same thing except it would not get into 5th. He was going in for the tranny when he noticed the u joint was bad.