Mystery Noise....Help : V-Twin Forum: Harley Davidson Forums

Seahag · 10-16-2005, 03:39 PM

Just got back from a 700 mile weekend getaway. A rattle that sounded like it was coming from the rocker boxes while riding developed. In the beginning I couldn't get it to make the noise while stopped and reving the motor, but by the end of the trip I was able to reproduce it and I think its localized to the left side.

It is definately NOT pinging. It doesn't seem to do it at all until revs are between 2500-3000...Then it sounds like something is loose and getting knocked around inside the motor. It doesn't change frequency or anything as the revs rise, and didn't cause the motor to lose any power or performance.

I'm going to borrow a buddy's mechanics stethoscope tommorrow and see if I can localize it. My early guess was one of the pushrods jam nuts loosened and backed itself off...but now I'm leaning more towards a possible compensator sprocket nut coming loose....but I thought that was only a problem on 03 and later models

I know its hard for you guys to diagnose a sound you can't hear, but I'm hoping you have some ideas to help me narrow the search atleast. I know quite a few have had compensator problems here, so maybe they could describe the sound that tipped them off.

Thanks in advance

Clay

P.S....If it is a compensator nut come loose, would I have done any damage by finishing my return home trip before getting it fixed?

HDMD88 · 10-16-2005, 04:43 PM

Quote:

Originally Posted by Seahag

Just got back from a 700 mile weekend getaway. A rattle that sounded like it was coming from the rocker boxes while riding developed. In the beginning I couldn't get it to make the noise while stopped and reving the motor, but by the end of the trip I was able to reproduce it and I think its localized to the left side.

It is definately NOT pinging. It doesn't seem to do it at all until revs are between 2500-3000...Then it sounds like something is loose and getting knocked around inside the motor. It doesn't change frequency or anything as the revs rise, and didn't cause the motor to lose any power or performance.

I'm going to borrow a buddy's mechanics stethoscope tommorrow and see if I can localize it. My early guess was one of the pushrods jam nuts loosened and backed itself off...but now I'm leaning more towards a possible compensator sprocket nut coming loose....but I thought that was only a problem on 03 and later models

I know its hard for you guys to diagnose a sound you can't hear, but I'm hoping you have some ideas to help me narrow the search atleast. I know quite a few have had compensator problems here, so maybe they could describe the sound that tipped them off.

Thanks in advance

Clay

P.S....If it is a compensator nut come loose, would I have done any damage by finishing my return home trip before getting it fixed?

I'd say it sounds like a loose primary chain adjustment...if it was the comp nut it should make a noise all the time as its running on the primary. The only damage it will do is mar the inside of the primary case.

LAF · 10-16-2005, 06:11 PM

It took a while for me to find, localize my loose comp. nut. If it is just starting it is intermittent then it progresses to a full time noise. At least was my experience when it coincided with my new build. If you pull the inspection cover and get your fingers on the sprocket and try to wiggle it you would know pretty quick, four screws is all. Might be worth the 15 mins. for piece of mind. I use a long screw driver with the correct torque head bit.

It is very odd on these comp. nuts, mine 4200 on my 05.

Seahag · 10-16-2005, 09:36 PM

Quote:

Originally Posted by hdmd88

I'd say it sounds like a loose primary chain adjustment...if it was the comp nut it should make a noise all the time as its running on the primary. The only damage it will do is mar the inside of the primary case.

I would think that is unlikely as I have a Hayden M-6 tensioner, but I will check it out at the same time I try LAF's test of trying to wiggle the sprocket.

LittleBear · 10-16-2005, 09:49 PM

I had a Hayden M-6 chain tensioner on my bike and the damn thing screwed up somehow and allowed the chain to hit the inside of my primary. Just a heads up. Do not assume it is doing its job. It may not be.

GrayRider · 10-16-2005, 10:18 PM

Check your heat shields. Sometimes a loose one will rattle.

LAF · 10-16-2005, 10:37 PM

Quote:

Originally Posted by Seahag

I would think that is unlikely as I have a Hayden M-6 tensioner, but I will check it out at the same time I try LAF's test of trying to wiggle the sprocket.

Either way those four screws should tell you the story if it is indeed in your primary.

I have heard a lot on these primary chain tensioner going

up for no reason.

If it was me I would know by now as those four screws would have been out.

Seahag · 10-17-2005, 07:09 PM

Well I'm pretty sure its in the primary...as diagnosed with the stethoscope I borrowed from my friend...On a side note, its amazing what you hear with those things...I think I'm going to have to get one. Now I just have to put it up on the lift and do some exploring...but first I think I'll read up on that compensator nut job, since I believe that may be the problem. Thanks for the tips all...now if you have any helpfull tidbits for the job at hand, it would be appreciated if you'd share.

Thanks again.

LAF · 10-17-2005, 08:18 PM

Yes they are amazing to listen through. Dynatherapy bought me one as an after build gift.

I chased all my bolt holes and blew them out with brake cleaner and then air. since you are making dirt anyway and changing fluid perfect time to make sure they are pristine.

Tips? Well I used a piece of that orange frame rail stuff you use to protect cars and bikes on lifts as my wedge material.

I had a new primary gasket but did not use it as the gasket stayed on the case so I left it.

You may want to get the shim kit for it. however I did not.

I went to 150 on the torque but have seen others talk of 160. Liberal dose of red locktite on mine.

It has lasted 8000 miles so far on the new build so it must have worked. That is twice the mileage it lasted new from factory.

Am really curious what it is you hear I mean at the end it was a very nasty sound from the comp nut. Not like a sloppy chain as I know what that sounds like from another bike that had the 1000 mile done at the dealer. but that is another thread

Seahag · 10-17-2005, 08:38 PM

When I was riding the bike the sound must have reflected off the wind deflectors on my forks and the inner fairing for me to hear it so clearly.

The only way I can describe it is that it sounded (and I feared) like a bolt came loose in the rocker box assembly and was being bounced around in there by the action of the rocker arms....only not as loud as you'd immagine that would be. It was a definate metal on metal clatter independant of rpm for its frequency.

Once I put the stethoscope on it every other part of the motor and tranny sounded very smooth and sweet; but the primary, more noticably in the front near the shifter arms, sounded like there was some loose change being slowly tumbled inside.

Thats the best I can describe the noise...I'm just happy that everything in the top end and tranny sounds nice so I won't have to worry about a major teardown.

LAF · 10-17-2005, 08:52 PM

I am rooting for you for sure and glad it was not on the top end. I don't know what a auto chain adjuster blowing up inside there would do though.

I can tell you bouncing off the fairing and the general sound of these bikes sounds will fool you easily. That stethoscope don't lie though.

Don't you have those four screws off yet

Seahag · 10-17-2005, 09:47 PM

Quote:

Originally Posted by LAF

I am rooting for you for sure and glad it was not on the top end. I don't know what a auto chain adjuster blowing up inside there would do though.

I can tell you bouncing off the fairing and the general sound of these bikes sounds will fool you easily. That stethoscope don't lie though.

Don't you have those four screws off yet

I admit I'm procrastinating. I don't have a garage and my driveway is sloped so if I want to use a lift, I end up wrenching at the bottom of my driveway on the edge of the street. Up till this point, I've managed to make it through every riding season without wrenching other than oil changes. I save all the real work for winter time. With it getting so close to the end of the riding season, I'm just wondering if its worth the hassle of jumping into it on the street, or taking it to the Mother in laws for winter storage and adding it to the "to do" list for winter.

LAF · 10-17-2005, 10:22 PM

Just funning on the screw thing....sorta.

I would take it to the bottom and just take the screws off and see at least know what you are in for.

I guess either way you have to take the primary off if either of them is FUBAR.

The comp nut can be done in a small amount of time as it is not too bad to do. I still got another month or so to ride so the couple hours would be worth it to me. I see your just a bit NW and I imagine your weather is starting to change. I have a much better working conditions a car port, it is flat though

mlewis · 10-18-2005, 10:22 AM

I had the same kind of noise occur when the rubber kick-stand bumper (frame mounted) rotated such that it allowed the tip of the kick-stand to rattle against the bottom of the primary cover.

Seahag · 10-18-2005, 10:35 AM

Quote:

Originally Posted by mlewis

I had the same kind of noise occur when the rubber kick-stand bumper (frame mounted) rotated such that it allowed the tip of the kick-stand to rattle against the bottom of the primary cover.

I'll double check that too because the noise I heard in the primary didn't seem loud enough to be heard as clearly as the noise I heard going down the road...and of course I had the kickstand down when testing.