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Cat D4G hydrostatic drive problem

Discussion in 'Dozers' started by wsw, Jan 27, 2011.

  1. wsw

    wsw Well-Known Member

    Joined:
    Jan 27, 2011
    Messages:
    122
    Location:
    ontario Canada
    Anyone out there familiar with D4G hydrotatic drive problems? the machine runs alone at the speed you set and all of a sudden the speed guage drops to the bottom and the machine goe to a real slow crawl, you play with the speed selector buttons and it comes back but not always right away. have done presser test and all tests o k, it seems to be electrical sometimes it takes a few minutes before you can get the needle on the speed guage to come back up
     
  2. dsichewski

    dsichewski Well-Known Member

    Joined:
    Sep 14, 2009
    Messages:
    93
    Location:
    Kitchener Ontario
    the joystick bow-tie sensors might need to be recalibrated?
     
  3. d9gdon

    d9gdon Senior Member

    Joined:
    Feb 12, 2010
    Messages:
    1,491
    Location:
    central texas
    Speed problem

    I bought one new in 2003 and soon after there was a recall on them about a screw in the joystick falling out. The dealer came out and put one in that was coated with locktite to fix it. I think maybe this would only have to do with steering though because I saw him do it and I think there were two switches in there, one for left and one for right.

    I also had trouble with a speed sensor located at the back of the machine. There's one for each side of the hydro drive. It was only leaking oil because it was plastic and had cracked for some reason. I know that if one goes out you will have problems with the machine tracking straight cause I had one rented that did it and come to find out it was a bad wire in the harness going to that speed sensor that had broken. The dealer jumpered the bad spot for me out in the field and it tracked straight after that.

    First thing I would do is to haul it in to the dealer(or maybe an independent would have the computer to test it) and have them hook their computer to it to diagnose it. There's so many variables going on that it could just be a bad wiring harness or sensor. I'm sure it's an electrical problem from what you're describing.
     
  4. d9gdon

    d9gdon Senior Member

    Joined:
    Feb 12, 2010
    Messages:
    1,491
    Location:
    central texas
    wsw,

    Just wondering if you had any progress with your machine or had it diagnosed yet.
     
  5. wsw

    wsw Well-Known Member

    Joined:
    Jan 27, 2011
    Messages:
    122
    Location:
    ontario Canada
    NO WE WILL GET AT IT NEXT WEEK, i AM A CAT MECHANIC BUT MORE USED TOO THE BIGGER STUFF,
     
  6. Temu

    Temu Well-Known Member

    Joined:
    Mar 26, 2008
    Messages:
    132
    Location:
    California