rattling noise in higher gears, light throttle

Discussion in 'Transmission' started by Keene, May 12, 2015.

  1. Keene

    Keene New Member

    A "rattling" noise that's a combination of marbles and valves is getting louder on my bike (2010 Heritage Softail Classic) and I'm having trouble identifying where it's coming from. It's primarily when in the upper gears (4, 5, 6) and at light throttle (enough to maintain speed). It's there when I accelerate but not as noticeable. Same with decelerating. When I pull in the clutch and rev the engine there is no noise. Let out the clutch and it's immediately there. So it's drivetrain related but I'm not sure where to start since it's hard to diagnose and pinpoint the sound location when running down the road. Thanks for any suggestions.
  2. Jeff Klarich

    Jeff Klarich Well-Known Member Contributor

    Check your belt guard.
  3. dolt

    dolt Senior Member

    Could be several things going on.

    First place to look is the inner primary, specifically the compensator.

    Other potential sources would be the inner primary bearing/race and the big main shaft bearing behind the drive pulley.

    Unfortunately, none are easy or cheap to repair.:coffee
  4. Jack Klarich

    Jack Klarich Guest

    What fluids do you use in primary and tranny, and does it do it in neutral also?
  5. Keene

    Keene New Member

    I recently changed fluids (14K miles on the bike) to Amsoil (20W-50 engine, V-Twin Synthetic Primary Fluid and V-Twin Synthetic Transmission). Replacing the tranny oil Harley had in there (I picked up the bike used from Harley with 10K miles last fall), made an improvement in smoothing out the shifting and finding neutral. There's no "rattling" sound in neutral with the clutch engaged. I can hear it in 1st through 3rd gears (not accelerating but just holding speed with light throttle in each gear) but becomes more noticeable in 4th through 6th gears, again light throttle holding speed (lessens under acceleration, some noise when decelerating). The noise becomes more evident as the bike warms up (it's quiet when it's cold). I tried the start/stop procedure to adjust the primary chain but there was no change. The drive belt appears to be the right tension so it shouldn't be slapping the cover shield and I would think the belt would still make the sound even if I pulled in the clutch while moving down the road. The sound immediately stops when I pull in the clutch and starts up again as I let out the clutch so it's clearly drive train related but I can't pinpoint it.
  6. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

    My point of thought if the noise stops when the clutch is pulled in while the bike is moving then the belt will still be turning the gearbox will still be turning and the primary will still be turning
    But there is no loading on the drive train so perhaps a bearing is starting to fail
    Perhaps it is time to start stripping the primary and checking everything as the problem may be evident by a visual inspection

  7. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

    +1 on what Brian said. You have narrowed down and it sounds like the primary needs to come apart for inspection.
  8. stray dog

    stray dog Junior Member

    +1 on all above.
    I think it's time to stop riding & start wrenching, you don't want either one of these bearings to totally fail. :(
  9. stray dog

    stray dog Junior Member

    If you do not have a service manual, its time to get one.
  10. Jack Klarich

    Jack Klarich Guest

    #1 on this advice:s