High pitch chatter noise at idle only.

Discussion in 'Transmission' started by CropdusterDoug, May 29, 2011.

  1. CropdusterDoug

    CropdusterDoug Member

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    I thought it may have been caused by worn transmission bearings, so I bought the rebuild kit, a new drive belt (60,001 miles on the bike), all of the special tools ($$$$) to disassemble the transmission, because I'm a do-it-yourself guy. Also bought a hydraulic press to press the bearings out. Pulled the transmission out of the frame and replaced all of the bearings. Didn't notice anything wrong except for a noisy main shaft bearing, and noisy shaft bearings. Took me a few days to reassemble the tranny and stand back proudly looking at my mechanical "skill." Fired the engine up to discover the noise is still there? My jaw dropped. :( Now the possibly is that the starter pinion gear may be making contact with the ring gear in the chain case, but there wasn't any abnormal wear on the pinion or the ring gear when I took them out? The Harley dealership mechanic and an independent Harley shop mechanic both couldn't figure out what the noise is? Does anybody have any clue as to what this problem is?

    I forgot to mention that there is a possibility that the copper washer on the end of the starter pinion shaft may be spinning up to speed on the clutch pack because of wear? I'll try that one too.
     
    Last edited by a moderator: May 30, 2011
  2. marcus22

    marcus22 Junior Member

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    exhaust? its hard to understand your definition of high pitch chatter over the internet but I have, what I would call, a high pitch chatter comming from my exhaust. hope you get it figured out without spending too much more money.
     
  3. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    Without actually hearing the noise it's hard to say what it is, but I would look at the clutch and clutch basket.
     
  4. BUBBIE

    BUBBIE Well-Known Member

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    How long has it been since the primary chain has been changed and the sprockets looked at for ab-normal wear..

    If the chain has never been changed OR a too loose-tight adjustment ,,,, it might a source of the noise...

    signed....BUBBIE
     
  5. CropdusterDoug

    CropdusterDoug Member

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    Well I've ruled out the starter sticking and the starter shaft thrust washer too loose. I'm now thinking that the noise originates from the engine crank case. I'm going to find an independent shop specializing in older bikes and get their opinion.
     
  6. Jack Klarich

    Jack Klarich Expert Member

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    Check the primary like Bubbie said, look at the shoe on the tension-er and pay close attention to the chain and front sprocket, pull the clutch in does it still make the noise could be a noisy throw out bearing
     
    Last edited: May 30, 2011
  7. CropdusterDoug

    CropdusterDoug Member

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    Looks like I'll be pulling the engine and disassembling it this winter. What I'm hearing is a gear noise in the engine case. When turning the engine off, just as the engine comes to a complete stop, it "grunts." Rather than buying all of the specialized tools, I'll pull it apart and have a shop with the special tools do what I can't. I figure that I'll save a few bucks if I only disassemble and reassemble the case and parts. Those specialized tools are just too expensive for me to buy. The cylinders and head are no big deal for me to work on. That's what I once did for a living.

    To rule out clutch and chain as the origin of the noise, I installed a new chain. The friction discs and plates of the clutch measure within limits and were not changed. While the chain case cover was off, I stated the engine. It's a gear noise inside the engine case...this coming winter's next project. Forgot to mention...there is no throw out bearing on my clutch. It's a simple contact point on the adjuster capscrew. The clutch pack bearing is new.

    The latest in my "learning" process. After installing the new primary chain, about 90% of what sounded like an engine gear noise disappeared. You guys were right about the chain although holding them side by side I can't see any difference in length, but it was obvious in the chain adjuster slack difference. Now I'm thinking that perhaps the primary sprocket should also be replaced too. Maybe ALL of the noise is because the chain and worn sprocket teeth, although the teeth look okay? My diagnostics have been 100% wrong so far so nothing will surprise me. Oh, and I measured the clutch pack thickness and it's within the middle of the wear tolerance. Measured each friction disc and drive disc. The adjuster for the clutch spring compression is in the middle holes and the spring is perfectly flat, so that's no problem. Sorry for beating this subject to death, but maybe somebody else may find themselves having the same problem that I did and won't do the blunders I have done in trying to find the problem.*After installing the new chain, the "gear noise" remained, but after riding around for a couple of hours, it all but disappeared?
     
    Last edited by a moderator: Jul 7, 2011
  8. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    Doug it's post like yours that really help all of us. Ride safe
     
  9. CropdusterDoug

    CropdusterDoug Member

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    Ready for this one?....the noise came back! I had enough of it and pulled the chain case completely off in preparation to pulling the engine. I pulled the alternator rotor off. In the process of unscrewing the torx screws holding the stator windings onto the engine case, I discovered three of the screws had sheared. A closer look indicated rubbing against the inside of the rotor. There were chattering marks indicating this had been going on for a long time. The chain case oil had been very dark, probably from the carbon in the rotor magnets rubbing off. Can it be that simple, I thought? Had to use a reverse twist drill bit to remove the broken screws. One of the screws was frozen solid. Had to try using an easy out. That easy out broke-off in the screw making it impossible to remove the screw. Drilled a new hole in the stator adjacent to the broken-off screw. Used that new hole as a guide to drill and tap threads into the case. Since it was necessary to pull that 22 amp stator off, I replaced it with a 32 amp stator, new rotor, and voltage regulator.

    It's been a while since posting on this thread because I wanted to make sure this wasn't another one of those mis-diagnosis that has plagued me with the what I thought was gear noise. Basically, this event has been a cluster you know what. However, the problem is finally fixed, and I don't have to disassemble the engine after all. Glad that's all over. Next trip will in be in about two weeks: Reno to Seattle to visit the Boeing Aircraft Museum. Oh, and I also stopped by the two Harley shops to let the mechanics know what I found. They were both surprised as much as I was. At least now they know if someone with an older bike comes in with a similar noise that they heard, they'll have a better idea of what it probably is.
     
  10. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

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    CD,

    Glad to hear you got it sorted out. Sometimes it takes awhile with this kind of thing. Just think how long and how much it would cost if you had taken it to the Dealer? Thank you for reporting back what you had found. It very well may help someone else here out one day.

    Bodeen