Grinding in Primary

Discussion in 'Transmission' started by stray dog, Jul 15, 2008.

  1. stray dog

    stray dog Junior Member

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    Hi to all-I'm a newbie here-great forum!
    '03 road king w/13,700 mi.

    I have a grinding noise & vibration coming from the primary. It happens when bike is cold in neutral with clutch in or out idling but once clutch is in and in gear its less or not at all. Also when warmed up in neutral with clutch out. I can also hear it a little down shifting into 2nd and alot more to 1st (not heavy down shifting either).

    Also cold in neutral I can roll the bike and it will go away at certain spots.

    Fresh HD+ in tranny & primary, chain adjustment looks good, adjuster shoe worn about 1/16", belt tension is good also-I also tried loosening it just a bit with no help. Clutch is also adjusted with no real signs of slippage. The bike shifts and finds neutral great.

    Been reading the HD bible trying to wrap my brain around clutch packs, compensating sprockets & transmissions!!!

    Any ideas or help welcome!!!!!!!
     
  2. glider

    glider Veteran Member

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    First thing comes to mind is the compensator sprocket or the stator magnets loose.
     
  3. stray dog

    stray dog Junior Member

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    glider,
    first off thanks for putting this post in the correct place.

    what does the compensating sprocket do, keep the chain lined up? and how can you tell if it's bad?
     
  4. glider

    glider Veteran Member

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    Usually if the comp sprocket is bad or loose, it will give you a knocking noise like a bad rod bearing. It basically absorbs the power pulses from the crank to smooth out the power transmission through the primary chain using ramps that load and unload when the piston is forced down in the power stroke. There is a spring that forces the two halves together that gets compressed on each power stroke then unloads to give you a smoother ride. In other words it takes the shock out of the drive train.

    [​IMG]
     
  5. stray dog

    stray dog Junior Member

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    Thanks for your time glider,
    Bought some tools & did some wrenching.
    The needle bearing on the tranny side in the main drive gear walked to the under-cut on the tranny main shaft.
    Why would this happen? Not enough press fit between bearing & bore of main drive gear?
    Or could this happen because of bad procedures tightening the drive belt, or vehicle allignment?