John Deere 757 Clutch Questions

Discussion in 'Lawn Mowing' started by p7m8hk, May 29, 2009.

  1. p7m8hk

    p7m8hk LawnSite Member
    Posts: 17

    I was mowing last night with a JD 757 w/ 25HP Kawasaki and I noticed the charging light came on, which was followed by a "hot" electrical smell. I shut it down and found the connector to the clutch was melted. I clipped the burnt/melted connector off and took an ohm reading across the coil and I got .3 ohms which I thought was way too low. The called the local JD dealer and he said it should be 2.6~2.8 ohms which seems right to me but, why did it not blow the 20 amp fuse before it melted the wiring? At .3 ohms it should have been pulling about 42~43 amps @ 12.8 volts. I replaced the 20 amp fuse with a 15 and started it up engaged the blades, blades kick on and run but charging light comes on but it as never blown the fuse. Any ideas??

    Also, the machine only has about 320 hours on it. What type of life do you guys/girls see out of these clutches? I always service the mower and use a blower to cleanit off daily and it is washed weekly. It will cost me $285.00 for the part and that's me putting it on. Any ideas on what I could be doing wrong or ways to extend the life of the clutch?

    Thanks for you time

    Clete
     
  2. WPLE

    WPLE LawnSite Member
    Posts: 153

    My 737 was doing something similar, minus the melting. But my light would stay on and clutch was acting up. Ended up the battery was to small. Just a thought.
     
  3. 4.3mudder

    4.3mudder LawnSite Silver Member
    Posts: 2,227

    Electric clutches that I have read up should be shut on and off with the engine at the lowest RPM possible. Idle would be great to engage, but may not be possible so a little above idle to engage is better than WOT, but at idle to disengage would be fine. Clutch may be going out, but only around the amount of hours you have put on it is low, but depends on how you engage/ disengage the blades.
     
  4. MJB

    MJB LawnSite Silver Member
    from Wa
    Posts: 2,869

    Watch the bearing in the clutch it will cause it run hotter melting th wires until the bearings go out and kill the motor. You might notice a different sound like metal sqeaking right before it goes. They are nothing to change by yourself on most machines.
     
  5. p7m8hk

    p7m8hk LawnSite Member
    Posts: 17

    Thanks for the replys and the information. Any thoughts on why it didn't blow the fuse? Seems to still spin free and no new noises. Should I be doing any type of PM on the clutch?
     
  6. rcw4235

    rcw4235 LawnSite Member
    from Ohio
    Posts: 1

    It seems I too have the same problem with my PTO clutch. Got the smell burnt wires, running hot, running battery down. I tried to removed the clutch but not sure which direction to loosen the nut. Facing the rear of the 757 looking at the clutch I turn the nut counter clockwise,,right? How does one keep the engine from turning? I put a vise grip chain but it really won't hold.,,if I can get the blot out I got a wheel puller. Any help,,grass is growing...thanks
     
  7. JohnBanks

    JohnBanks LawnSite Member
    from Kansas
    Posts: 181

    I never had that problem on my 737, I guess I got lucky. Take it to Deere and make a fuss about the hours, that shouldn't happen. I used to turn my off and on a ton, at full speed, low speed, I didn't try to baby the clutch, and never blew one. My last Deere I just traded in squealed like the clutch was trying to go out.. but didn't keep it long enough for it to break or blow heads again..
     

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