Bobcat PredatorPro deck vibrations

Discussion in 'Lawn Mowing' started by txcharlie, Jun 7, 2009.

  1. txcharlie

    txcharlie LawnSite Member
    Posts: 6

    Just purchased a 33/61 PP. I have a vibration in the mower deck. It is very noticable at 1/4 and 1/2 throttle. At full throttle, it's not as bad, but there is alot of play in the belts while running. I thought the blade(s) were bent from the shipper not using long forks when loading the palet onto the trailer. After inspecting the blades, I can not see any damage. Is it possible the blades were slightly bent, like 2mm, and causing the vibration?:usflag:
     
  2. Mowingman

    Mowingman LawnSite Platinum Member
    from Texas
    Posts: 4,647

    Betteer have the dealer take a look at it. Could be a slightly bent spindle shaft or an out of round pulley. A very slightly bent blade will usually not cause a bad vibrtation. If the bend is noticable, then the blade could be the cause.
     
  3. puppypaws

    puppypaws LawnSite Fanatic
    Posts: 8,857

    You have definitely got a problem, coming from no fault of yours. The dealer needs to take your mower and get it straightened out. It may be no more than a blade problem or something as severe as a warped deck. It could also be a bad belt or pulley, it is not your responsibility to be concerned. This is Bobcats responsibility, let us know what is done?
     
  4. kaferhaus

    kaferhaus LawnSite Bronze Member
    Posts: 1,444

    It's either out of balanced blades or a bent blade OR the spindle spacer between the blads and spindle is "cocked"... I've seen that one... the blade will look tight but the spacer can "****" on the spindle, gaul and wedge a bit sidways... but that usually causes a vibration at all speeds. I'm betting it's the blades.
     
  5. Lawn Pawn

    Lawn Pawn LawnSite Senior Member
    from zone 3
    Posts: 568

    My new zero turn had TERRIBLE VIBRATION at less than full throttle when I would throttle back to mow slower in super dusty or bad ground conditions.

    Short version of story. Secured a rubber spacer under one tension spring to dampen vibrations.... and stretched a bicycle inner-tube over another tension spring. BIGGG improvement!!!

    No harm done doing this.... runs much smoother and quieter.
     
  6. puppypaws

    puppypaws LawnSite Fanatic
    Posts: 8,857

    I'm sorry, but if there is a bad vibration; something out of the ordinary is causing this to take place. The only thing you should hear is the wind turbulence under the deck when the blades are engaged, and feel no vibration. If you have a blade causing vibration from hitting something while mowing or being out of balance really bad, it will wear the spindle bearing out faster than normal, sometimes much faster.
     
  7. Lawn Pawn

    Lawn Pawn LawnSite Senior Member
    from zone 3
    Posts: 568

    You are 100% correct..... I did the above, and even replaced a spindle that was running warmer than the others. But in-fact it was a spring vibrating and pounding on the deck... for what ever reason. Personally I think it should be of a different tension... more clearance or a change in geometry in the bell-crank?

    The inner tube was just to fine-tune as it were a ...sympathetic.. I think that's the word to use.. vibration in a much longer and lighter duty spring that would vibrate in a circular motion depending on engine RPM.
     
  8. txcharlie

    txcharlie LawnSite Member
    Posts: 6

    Thanks for all the input. Will update when a solution is found.
     
  9. txcharlie

    txcharlie LawnSite Member
    Posts: 6

    Well, took it to local dealer and he replaced the deck belt. It is some better, but not a lot. I just don't run the deck at low speed and it works OK.
     
  10. Mowingman

    Mowingman LawnSite Platinum Member
    from Texas
    Posts: 4,647

    Check the groove in each belt pulley on the deck. You could have a small piece of wood chip, or a small rock down in one of those grooves. It will make the belt jump and cause a vibration.
     

Share This Page