Heritage has a new noise

Discussion in 'Softail Models' started by gasbag, Jan 21, 2010.

  1. gasbag

    gasbag Active Member


    My bike has developed a problem and I was hoping someone might have an idea as to what may be wrong.

    It is hard to explain. It is an engine/tranny rattling sound but it is not specific to engine speed, meaning it doesn't get louder as speed increases and the noise does not change pitch. It is always the same sound. The noise occurs at certain speeds but does not increase in frequency or loudness if I accelerate. The noise sounds like it is coming from under the front of the tank, maybe down low. My pipes aren't obnoxious but they are not stock and I can plainly hear the noise riding with a helmet. I had an old Triumph TR4 that had a loose timing chain tensioner. It sounds a bit like that only not as loud.

    The noise occurs ONLY at these times; the speeds are approximate.

    1st gear: 14 to 18 mph
    2nd gear: 24 to 28 mph
    3rd gear: 34 to 38 mph
    4th gear: 44 to 48 mph
    5th gear: 54 to 58 mph

    NOTE: in between those speeds there is no unusual noise whatsoever.
    As I run up the gears the noise gets more noticeable. I assume that is because as the bike gets up to cruising speed everything is quieter and the noise becomes more apparent. In first gear it is hard to hear.

    If I am cruising at 56mph in 5th the noise is very apparent. If I pull in the clutch the noise goes away as I coast down the road. If I re-engage the clutch the noise returns. Also, if I decelerate the noise will change a little and get a little louder.

    My dealer found a compensator sprocket loose, whatever that is. They said they tightened it. No change.

    This noise is so speed specific I can actually ride around and avoid hearing it just by altering my shift pattern. There are no vibrations and I have full power. The bike runs great. Well, except for this noise.

    I don't like bothering people with my problems, but this noise has me stumped, and obviously my dealer at the moment. Any help or suggestions or like experiences would be much appreciated.

    Thanks for listening.

    Have a good day and ride safe.

  2. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    First, when the bike is cold or at least not more than warm, grab hold of stuff and really man-handle it to see if you can find something loose. See if you can get the gas tank to move up and down. Try to get the heat shields to move, or the pipes to move in their brackets. Get someone to steady the bike, and see if the jiffy stand easily moves up and down when in the "up" position. Grab the tins and see if they are loose. Keep checking everything that should be tightly fastened to try to find something that isn't. No luck? Then read on:

    When my compensator nut (actually called a Sprocket Nut and is #66 in the first schematic) backed off, it allowed the rotor (#24 in the second one) to wallow around enough to jam agains the stator coils (#27). When that happened, the drive shaft neatly sheered off all the teeth in the hole in the rotor. This also allowed the rotor to wabble and made a rattling sound. So, based on the fact that you say the Dealer already determined that the compensator was loose, I would go back in there and pull the compensator, clutch basket and chain off and then remove the rotor to see what you see inside there!! Might not be pretty!


    BELTS, CHAINS, & SPROCKETS - 2006 Harley Davidson Softail Heritage FLSTI

    ALTERNATOR & REGULATOR - 2006 Harley Davidson Softail Heritage FLSTI
  3. 2000classic

    2000classic Active Member

    Add shift linkage to the things to check for rattle. I had a shift rod that set off a pretty good buzz at certain times.:(
  4. Hoople

    Hoople Account Removed

    I agree with TQ. I would say something in the compensator, rotor area. I would guess that within those 5 windows of road speed you mentioned, the RPM's are pretty close to each other.

    Just a guess but to me it sounds like the compensator springs washers are weak. You hit that resonant sweet spot and it starts to rattle.
  5. gasbag

    gasbag Active Member

    Thanks for the replies folks. My son and I are going to go over the bike this weekend and check everything we can and make sure everything is tight. If we find nothing, I have printed out everyone's suggestions and will take it to the dealer taped to the windshield.
    If I tried I would do more harm than good. I am not a mechanic. I don't even pretend to be one on a bike forum.:D

    NEWHD74FAN Experienced Member Retired Moderators

    One problem is you did not describe the sound, was it a metallic rattle sound, could be pinging to loose exhaust baffles, tin shroud or pinging. If it was a deeper sound good be involved in the gear train. If it is a loose or broken motor mount it could be at certain speeds engine is contacting something "bouncing around". TQ has a good list of things to check, I had a rattle and loose shifter linkage and baffles were the cause of my "noises"...found by gently tapping around the exhaust with my leather boot on the underside of the exhaust pipes and testing for loose hardware. When and where did you do the most recent work on your bike, it may offer a clue...

    BUBBIE Well-Known Member


    ON MINE at the ROT rally down in AUSTIN TEXAS this last year,,,,

    I had a clik-clank noise coming from my bike....usually 2500 rpm it would show up...checked everything...

    FINALLY FOUND IT..... the RUBBER BUFFER to FRAME on the kickstand was missing... a $3.50 item

    FOUND a few other bikes at MOTEL had the same MISSING rubber part ,,,,Probably some KID and a sharp KNIFE did the trick... OR?

    MUCH better than a scared up paint job..... so go figure. WHY?