keep burning belts on John Deere

Discussion in 'Lawn Mowing' started by Eagleseye, May 11, 2008.

  1. Eagleseye

    Eagleseye LawnSite Member
    Messages: 45

    Had a contractor give a John Deere walk behind HD 45. They had this mower for their spec houses, but hired me to maintain them. Mower has about 150 hours on it and is about 5 years old. It's like a new machine, but the tension belt under the deck only lasts about 5 hours of mowing. You have to keep tightening the tension throughout operations. The belt seems to scraping on something, because it just reduces in size and then breaks.
    I have removed the hyd pumps, told their good by hyd business here.
    I replaced all pulleys under deck and ensured proper alignment.
    The local JD dealer does not even a spec book on this machine, and I been dealing with this dealer for about 12 years. Talked to all the mechanics about the problem and they just look at me and say " Huh crazy"
    Any thoughts
  2. Albemarle Lawn

    Albemarle Lawn LawnSite Bronze Member
    Messages: 1,544

    If gas wasn't so $ I would offer to come buy it!

    The HD has been the most reliable walk behind for us and just last year I bought another one new-old-stock. I like their short overall length compared to the current Deere walk behind.

    There should be a sticker on the frame indicating correct belt tension. Don't have my mower here, but the sticker shows I think 14mm-16mm of spring between the frame and castle nut/washer. This is very important, and you must use a JD original belt for this tension to be correct.

    This is the weak point of this machine, but even still you should get about 300 hours out of the belt. The idler is a "puller" as opposed to a typical "backside of belt" idler.

    Looking under the mower, the idler bracket should be free to move when its supporting bolt is tight. I like to put just a little heavy grease such as disc brake caliper grease on the sliding surface to allow the tensioner to pull efficiently on the belt.

    Finally, I think you said you replaced pulleys, pay close attention to the pulley on the motor, it is a cheap tin welded pulley. It can crack or separate at the welds. If it fails you may try to find a nice cast replacement.
  3. Albemarle Lawn

    Albemarle Lawn LawnSite Bronze Member
    Messages: 1,544

    "have replaced all pulleys under deck"

    The machine has 3 belts. One for the hydros, one on the deck, and a PTO belt that takes power to the deck.

    The hydro pump belt has no contact with the deck pulleys so the pulleys you replaced are not relevant to the problem you are having.
  4. deereequipment

    deereequipment LawnSite Senior Member
    Messages: 370

    I just replaced that belt this weekend on my HD75.
    Pain in the but, but thanks for the note of paying attention to the 14mm-16mm.
    I'll double check it.

    Love my machine, and me too, do not have any books from my dealer.
    Ask the mechanics there, they dont' know anything about them.
    I guess that means they don't break down that much!!

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