Annoying drive belt "chirp"

[Ken R]

'02 Ultra Classic:

I can easily see why it chirps. 

The final drive belt is riding at the left limit of the rear wheel pulley.  The pulley has a few thousandths wobble.  The chirp is synchronous with the wobble. 

There's maybe 50-thousandths of an inch between the right side of the belt and the right-hand pulley flange.  But the belt is pretty much touching the rear wheel pulley of the left side flange. 
Same on the top of the pulley as the bottom. 

With the axle cams on this year's bike, I assume that the rear wheel is aligned correctly.  Belt tension adjusted to manual. 

I could simply put some very thin washer spacers between the pulley and rear wheel hub.  But it would seem that would be masking a problem with a band aid.  I'd rather fix what's there.

The right side of the drive belt has always caused a shiney band on the rear tire.  It would be even closer if it tracked in the center of the rear wheel pulley.


Any ideas?

Ken

[barny7655]

Use some silicone spray , on that side of the belt , then test drive it ,and also  i think your belt is a tad loose as well, even though you have done to the manual , cheers Barny

[baldoldfxr]

Maybe worth checking the engine /gearbox alignment ? there is a good tool for this in the tools section.

[RK101]

If I'm reading this right.Your saying the belt is rubbing on the left hand side of the pulley. It is also rubbing the tire on the right side. What size tire do you have on the bike? If I'm reading it right it sounds to me like the tire is pushing the belt to the left hand side of the pulley. If everything is in alignment it should not be hitting the tire like your saying. It sounds to me like you have to big of a rear tire on the bike that not letting it track the way it should. Either that or something is still way out of alignment. You didn't say if you've owned this bike since new. Is  it possible that a previous owner has layed the bike down at some point?

[Ken R]

If I'm reading this right.Your saying the belt is rubbing on the left hand side of the pulley. It is also rubbing the tire on the right side. What size tire do you have on the bike? If I'm reading it right it sounds to me like the tire is pushing the belt to the left hand side of the pulley. If everything is in alignment it should not be hitting the tire like your saying. It sounds to me like you have to big of a rear tire on the bike that not letting it track the way it should. Either that or something is still way out of alignment. You didn't say if you've owned this bike since new. Is  it possible that a previous owner has layed the bike down at some point?

You are reading it right except that the tire isn't "pushing" the belt over.  The clearance is very slight, though.  Just enough that if you look very closely, you can see that the sidewall of the tire is slightly shinier than anywhere else.  It must touch occasionally. 

Stock-size rear tire.  Dunlop E-3, though.   When I tried stock-size Avons, the clearance between the belt and tire was less, maybe slightly touched most of the time. 

The pulley has a little wobble in it . . .maybe .020".   I'm going to measure it.

Ken

[RK101]

Ok Here's a long shot have you ever changed the front motor mount or checked the motors alignment? Maybe one of the Hyme joint adjusters are bad. I just can't understand if the tire is the right size then why is it touching it at all if something is not out of alignment. My 04 has quite a bit of room between the belt and the tire and there's and inner guard there. Is it possible the swing arm bushings could be worn? I would suspect that you would feel that though while riding.
I'm not familiar with the profile of the Dunlop E3 tire compared to the OEM tire. Maybe I phraised that wrong by saying that it's pushing the belt to the left. Maybe it's touching just enough to not let it track straight either.  Good luck I hope some of this helped or at least gave you some food for thought.

[marc]

FWIW...I thought I had the same problem and it turned out to be the rubber muffler mounts...A little WD40 and no more chirp...

[relxn88]

 I have an 02 ultra and my squeek was caused by the belt not having enough tension. Whenever I let off the gas, the belt would chirp. Your right about not much room between the 1 1/2" belt and the tire, but if the rear tire is adjusted properly(and you have a 130 tire) there shouldn't be anything touching. just my 2cents.

[adayrider]

I have an 02 ultra and my squeek was caused by the belt not having enough tension. Whenever I let off the gas, the belt would chirp. Your right about not much room between the 1 1/2" belt and the tire, but if the rear tire is adjusted properly(and you have a 130 tire) there shouldn't be anything touching. just my 2cents.

Same thing happened to me. I wasn't holding the axle while I was tightening the axle nut and the first wack it would start chirping.     As far as the belt mine doesn't rub till I back the bike up and it rubs just a little with stock 130 continental tire.

[harleyjt]

02 was the first year for the new swingarm and axle adjuster setup.  The "nubs" on which the adjuster cams ride are very small compared to following years where they were beefed up.  You might look to see if one of those is worn allowing the axle to cock to one side.  One other thing to keep in mind is that the actual size of the tire can vary.  On my 02 I pick up a chirp that drove me nuts.  It started right after I intalled a new tire (stock Dunlop 402).  I checked everything I could, no problems were found.  I removed the wheel and tire and checked bearings etc.  The chirping finally went away on the next tire change.  It appears the tire I had installed was slightly wider than normal - and there's not much clearance there between the tire and the belt anyway. 

[CrazyRay]

Hey Ken, this was going to be my next topic since I just recently had all my junk apart, put it all back together and ...   the chirp. In fact it's a sustained chirp sometimes. Kind of a yodel. Maybe a chodel. Anyway, mine is a '99 and the belt has the "beveled" outside edge as well. I noticed it last year, what I believe caused mine was the rear wheel out of alignment. Which I have corrected.

"got any ideas?"

Oh yeah. On my bike that chirp always sings away whenever its wet. Have you ever noticed that? It's been like that since it was new. It doesn't have to be real wet either, high humidity will do it. When it dries out it goes away. But how do we explain the belt tunes when it's dry and everything has been checked and rechecked and we know it is all right?

I have a theory. I think maybe every time the belt comes off it needs time to be "re-seated" to the pulley. Think about it. Over time, each tooth on the belt gets "mated" to that corresponding groove on the pulley. That matched wear gets mixed up when the wheel comes off and then put back on. If it has been running for a while with the wheel a little cockeyed, for example, then both the belt and pulley develop a certain wear pattern that results from that alignment. Pull it then reinstall this time ensuring that the alignment is spot on, now the belt is rubbing harder in some areas and less in others than it was before. Now it starts to sing.

What I am doing this time is carefully double check to: a) make sure everything is aligned properly. b) make sure the belt is adjusted right and according to the book. Then I am going to mark the belt and pulley so I can put it back exactly like it was the next time it comes off. Might help I dunno, we'll see.

Does this make any sense at all or am I confused? As usual, this is just my theory and have no proof, yet. All feedback is welcome yea or na. The floor is open.

CrazyRay

[BK Meyers]

My brother has an '03 Road King that has had the same "chirping" noise coming from the belt on deceleration. I also noticed the noise on my '97 Heritage but pretty sure that was due to not enough belt tension. Have not had the problem on my '96 Road King.

Anyway, Harley makes/sells a rear belt lube that helps with the chirp. Last time I looked it was under $5 a tube. Doesn't take much. An odd note is that when I purchased my tube one of the salespeople (floor sales, not parts counter) told me that Harley actually no longer recommended using the lube, saying that it increased the chance of road debri adhering to the belt. 

Later,
BK

[Ken R]

My brother has an '03 Road King that has had the same "chirping" noise coming from the belt on deceleration. I also noticed the noise on my '97 Heritage but pretty sure that was due to not enough belt tension. Have not had the problem on my '96 Road King.

Anyway, Harley makes/sells a rear belt lube that helps with the chirp. Last time I looked it was under $5 a tube. Doesn't take much. An odd note is that when I purchased my tube one of the salespeople (floor sales, not parts counter) told me that Harley actually no longer recommended using the lube, saying that it increased the chance of road debri adhering to the belt. 

Later,
BK

Someone in another thread (on HTT I think) mentioned rubbing bar soap on the edge of the belt to see if it affected the chirp.  I haven't done that yet . . . .thinking that the alignment in the rear wheel pulley must be the cause. 

And RK101, you are right.   The inner belt guard IS in there and is actually what touches the wheel.  (I checked today).  I'm not sure that the belt touches the inside of the guard.   

[Ken R]

Ok Here's a long shot have you ever changed the front motor mount or checked the motors alignment? Maybe one of the Hyme joint adjusters are bad. I just can't understand if the tire is the right size then why is it touching it at all if something is not out of alignment. My 04 has quite a bit of room between the belt and the tire and there's and inner guard there. Is it possible the swing arm bushings could be worn? I would suspect that you would feel that though while riding.
I'm not familiar with the profile of the Dunlop E3 tire compared to the OEM tire. Maybe I phraised that wrong by saying that it's pushing the belt to the left. Maybe it's touching just enough to not let it track straight either.  Good luck I hope some of this helped or at least gave you some food for thought.

Ya know, one of the two times I took my motorcycle to the dealership was to get the alignment checked.  I tried it with strings, flourescent tubes, straight boards, etc. and finally decided to let the "professionals" at the dealership do it.  My back wheel is not centered in the fender . . . . off by about 3/8" to 1/2" to the left.  I thought, "This just can't be right."  So I took it to the dealership.

The service manager said, "We don't do alignment checks or alignments."

Me, "Really?"   

I asked them about the off-center rear wheel.  "Take a look at all the new Electra Glides on the showroom floor.  You'll see off-center rear wheels on most of them. Some much more than others."

They were right.  But it still bugged me that the factory-authorized dealer cannot (or will not) do an alignment check.   

So I guess I'm on my own.   I checked the "Tools" section  I can make the described alignment tool easily.  I'll re-read several times and refer to the shop manual to see if I can figure out how it works.

Ken

[vans24]

had that chirp , tightened the belt a little more and it stopped.

[Riverside Joe]

Had a chirp on decel at slow speed, may not be the same as what you have but like what Marc says, I wd40'd my ruber mounts under my saddle bags and it went away. Of course this was after I went from the front motormount thru to the cam'd rear wheel adjuster. Just my 0.02-------RJ

[Ken R]

Had a chirp on decel at slow speed, may not be the same as what you have but like what Marc says, I wd40'd my ruber mounts under my saddle bags and it went away. Of course this was after I went from the front motormount thru to the cam'd rear wheel adjuster. Just my 0.02-------RJ

There's no doubt about it.  The chirp I hear is from the final drive belt.  Standing next to the motorcycle on the dyno last week, it was obvious.  The chirp is perfectly in sync with the rear wheel speed, going up and coming down.  I could watch the pulley wobble slightly and the chirp was consistent with the wobble.  I'm going to measure the wobble today.  I think it's extremely slight.

Ken

[vans24]

you can lead the 
horse to water.. but you cant make him drink..

[ROADKINGKIM]

Just went through this on a buddy's bike and found the CHROME aftermarket pulley bolts had loosened up and 2 had cracks,
this allowed the pulley to wobble and the belt make noise. Put back the stock pulley bolts and realigned the rear wheel and no noise....Kim

[Ken R]

you can lead the 
horse to water.. but you cant make him drink..

It would seem that adjusting the belt to the factory specifications would be appropriate.  I hesitate adjusting the deflection more than specified for fear of ruining a belt. 

[Kleetus]

Ken,

You said "The chirp is perfectly in sync with the rear wheel speed, going up and coming down.  I could watch the pulley wobble slightly and the chirp was consistent with the wobble."

I've never seen a pulley firmly attached to a wheel that wobbled unless it was bent or had loose fasteners. Here's a long shot but could your pulley have got bent when the wheel was off getting a tire change?  I'm just saying...

Kleetus

[Ken R]

Ken,

You said "The chirp is perfectly in sync with the rear wheel speed, going up and coming down.  I could watch the pulley wobble slightly and the chirp was consistent with the wobble."

I've never seen a pulley firmly attached to a wheel that wobbled unless it was bent or had loose fasteners. Here's a long shot but could your pulley have got bent when the wheel was off getting a tire change?  I'm just saying...

Kleetus

Kleetus, that's been on my mind a lot. 
I've been trying to remember just when the chirping started.  Last two new rear tires were put on at the local indy shop.  They use a tire machine; which should be safer than tire irons with a good operator.  They may have indeed damaged it, but I couldn't say with any certainty.  If I'd changed the tire myself,  I'd have known for sure. 

Didn't get around to measuring the wobble today.  Maybe tomorrow evening.

Ken

[retyddone]

rk101 the 04 bikes had a 1 1/8" belt where the 02-03 had a 1 1/2" belt.

Tuna

[HIPPO]

Put the bike in the air and turn the wheel backwards several turns. If the belt now rides towards the other side of the pulley then the alignment provided by the axle cams is fine.

If I used anything it would be soap or the dealer has some stuff to rub on the side of the belt. Maybe just try washing the belt with soap and water first.

[Yukon]

my 94 FL had that chirp.....twice. Once at 75000 kms. and again at 145000 kms. Both times I literlly tore it apart and checked alignment and exhaust rubbers, pipes, bearings etc. The first time I couldn't find anything and the front motor mount let go on a road trip. I babied it home, replaced the motor mount and the chirp went away with it. The second time the chirp came back, I didnt think the motor mount was the problem because it looked tight so I went through the gammit of things again and came up with nothing. Out of desperation,I changed the front motor mount and once again the chirp was gone. It was always really bad when wet and fairly quiet when dry at the begining. As time went on, it became bad all the time. For what it's worth.

[stu058]

hey ken, don't know if you have stock pulley or not but my chirp was caused by a worn pm pulley that the teeth were worn down almost to a point. those teeth should have a round profile at the top. if you over thighten belt it will accelerate the wear. i would call phil at supermax.com. i installed a plastic pulley from him and couldn't be  happier. give him a call     stu

[vans24]

I apalogise , I didnt mean to give you bad advice, as we all know the  manual is always right. either way the extra 1/8 I tightend the belt  took care of my problem. but it is my bike and if the tranny  falls off or the belt breaks it is on me.  sorry again. hell it might not even be what's making the  chirp anyhow

[CrazyRay]

vans24,
I don't think that was bad advise necessarily. It is hard to get the belt tightness just right, especially doing it alone. Most of the time, tightening the belt a little more is what has worked for me. If we have to tighten it more than the manual recommends to get the chirp to stop, then maybe something else is going on. I think it is better to have a belt that might be slightly loose than one that is slightly too tight.

[Ken R]

I apalogise , I didnt mean to give you bad advice, as we all know the  manual is always right. either way the extra 1/8 I tightend the belt  took care of my problem. but it is my bike and if the tranny  falls off or the belt breaks it is on me.  sorry again. hell it might not even be what's making the  chirp anyhow

Vann, it wasn't the advice so much as it was the "horse" comment.   

I have time today and am going to try everything, including belt tension.  It is difficult to determine the right amount of deflection when alone; and even harder to tighten the axle alone after finished.  A couple of years ago when I had help and made sure that the belt was adjusted to the factory recommendations, I scribed a mark on each of the adjustment cams for future reference.  For the past couple of years, I've been simply aligning to the scribe marks tightening the axle nut, check to make sure it didn't move, and then quickly check to make sure the belt seemed to be adjusted O.K.   I'll be a little more precise this time.   As Hippo suggested, I'll rotate the wheel backwards to see if the belt moves to the other side.  I'm also going to check for cracks in the pulley, pulley bolt torque, and wobble.  Checking the front motor mount isn't easy with the oil cooler in place. 

I enjoy seeing other's pictures; so I'll take and publish a few if they illustrate anything worthwhile.

Ken

[ICANTD55]

This may help.
http://www.pingelonline.com/rear_sprocket_spacer.htm

[HIPPO]

I always used the method of twisting the belt between thumb and forefinger to check tightness.
Always check it with the bike cold, like after sitting overnight.

The other thing with these cam adjusters, the tension can't really be adjusted properly loosening and tightening. You start giving it tension, if you find you need more you can give it a little more, but if you find that it is too tight then it is best to start over from tension fully relaxed and both cams positively against the stops on the swing arm.

If you just loosen it a little it has a tendency to pull itself out of alignment because one cam is fixed and the other one has slack on the axle. Sometimes a new cam piece that fits better on the axle helps if the non welded cam has too much slack on the axle.

[hdpegscraper]

Ken, glad to see that your gona check out that front motor mount. Cause on my Dyna, if I raise the front of the motor, it will loosen the belt tension. Now you would prolly need a lot of travel to give you a problem, but its worth checkin.

[Ken R]

O.K. I did everything except engine/transmission alignment.  (Don't have the alignment tool yet). 

But I did use Frank's suggestion of rotating the wheel backwards.  Sure enough, the belt moves to the inside flange.  Back forward and it moves against the right-side flange.   Seems pretty even.   So for now, I'm discounting alignment.

Checked the swing arm locknut torque.  Had to add 4 ft pounds to get it to 40ft lbs.  Also checked the pivot mount bolts and torqued them to spec.  They needed additional tightening, too; to get there.  All this stuff is in the 10K mile check-up.  Haven't touched any of mine since almost 10K. 

Unbolted the oil pump and checked the front mount.  No cracks or anything.  The center nut was to specification.  (about 10K ago, it needed additional tightening, but not this time).

The bolt that goes through the eyelet on the front adjuster was loose.  I could almost turn it by hand.  But I don't think that it contributed to any problems (yet). 

After all of that, I checked belt tension.  It seemed rather light.  Spec says that it should be adjusted to 5/16" to 3/8" deflection when pushed up with 10 pounds of pressure without rider's weight.   (1/4" to 5/16" with a rider) 
Mine easily deflected to 1/2" to maybe even 3/4" with no rider. It was definitely loose despite that my scribe mark was still centered on the adjuster nub.  Has the belt stretched?  I didn't think carbon fiber belts would stretch.  (I know metal chains will, but thought carbon fiber stretch was minimal).   So I loosened the axle nut on the right side and adjusted the axle with cams from the left.  Didn't overshoot, so one adjustment did the trick.  I removed the left shock lower bolt, and then lowered the motorcycle to compress the right shock while on the sidestand to simulate a person on the motorcycle.  Removing the bolt also allows my 36mm wrench onto the axle. 

Put the covers, saddlebags, oil cooler, etc. back on and went for a little ride.  Didn't hear any chirp. 
Although I found maintenance that was needed, the drive belt not to spec was probably the culprit.  Using a centerpunch, I re-marked the position of the cams. 


I took pictures of everthing I did, but upon review, they seem worthless.  I won't take up the bandwidth. 

Edit:  Forgot to add that the wobble was .026", measured at the pulley flange.  I couldn't find a specification.  They may ALL be like that.

Ken

[HIPPO]

Good.
Temperature makes a difference on how the belts feel as far as tension. Here from summer to winter it can be 65 - 70 degrees easy. The colder the weather they looser they feel.

[Memnar]

My buddies 05 Soft tail had a rear drive belt pulley wobble - he bought it new and I think it had the wobble from day one fresh off the dealer floor. It squeaked a little but he couldn't hear it and only I saw the wobble.

So anyway maybe the rear pulley has the wobble from the factory....

[floatyguy]

Ken

My previous experiance with the "Chirp" (sounds just like a bird chirping on accleration and deceleration) is belt tension.
When you checked the tension did you have a person sitting on the bike that was equal to your weight or close to it? If I remember right the manuals say it must be checked with a rider sitting on the bike. If you have the belt tension tool (HD) the instruction will not say anyhthing about a rider sitting on the bike. On 5 speeds it should be 3/8in-5/16in with 10lbs of force applied to the belt when adjusting.

[Ken R]

Ken

My previous experiance with the "Chirp" (sounds just like a bird chirping on accleration and deceleration) is belt tension.
When you checked the tension did you have a person sitting on the bike that was equal to your weight or close to it? If I remember right the manuals say it must be checked with a rider sitting on the bike. If you have the belt tension tool (HD) the instruction will not say anyhthing about a rider sitting on the bike. On 5 speeds it should be 3/8in-5/16in with 10lbs of force applied to the belt when adjusting.

My '02 manual gives two specifications:  One with rider on the bike (1/4 to 5/16" with 10 lbs deflection) and one with rider off(5/16" to 3/8"with 10 lbs of deflection).  The manual doesn't say whether the motorcycle should be on the sidestand in the rider OFF condition. 

I jacked the bike up with my scissor jack, removed the left hand shock absorber bottom bolt. and swung the absorber out of the way.  Then lowered the motorcycle down and onto the sidestand.  The rear wheel suspension compressed approximately the same as with me sitting on the bike.  So that was my set-up.  It's as close as I can get to the specified adjustment.