Metro HP drive belt jumps sheave

Discussion in 'Mechanic and Repair' started by awdriven, Jul 18, 2006.

  1. awdriven

    awdriven LawnSite Member
    Messages: 31

    Hi guys,

    I have a Metro HP with a left-side drive belt that likes to ride 1/2 on the drive sheave from the transmission.

    It looks like it's been hit there, so I've ordered some new supports and a new idler weldment to see if that will help even up the belt. Any other ideas? If I set the belt properly on the sheave it will skip over in less than 10 feet of travel.


    More Pics -
  2. barnard

    barnard LawnSite Senior Member
    Messages: 618

    Check bottom belt guide for proper adjustment also is the left drive shaft bearing worn?

    FIXDISS LawnSite Senior Member
    Messages: 445

    From pics looks like the idler is not in proper alignment and also the bent bolt on the bottom stand-off may actually be forcing the belt to jump over to the inside groove.
  4. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    Looking at the wear pattern on the outside of that belt it appears it has been ran with that bent idler arm for a while. So don't be surprised if after you install the new arm the belt still jumps. It looks as though the pulley has put more pressure on the outside rib of the belt and more than likely stretched that rib more than the inside rib instead of stretching both ribs equal.

    FIXDISS LawnSite Senior Member
    Messages: 445

    Try bending the idler back in line and make sure it is riding level on belt. Mark the edge of the belt that is near tire then turn belt around with that mark toward frame and see if if tracks true .
  6. awdriven

    awdriven LawnSite Member
    Messages: 31

    Thanks for the advice guys, still waiting for the replacement arm to come into the dealer. In the mean time I replaced the 'shield spacer' and its bolt. Both were pretty bent. The behavior of the belt is the same and the whole assembly still doesn't seem square to the frame. Even with the new 'spacer', the outside edge of the belt still runs closer to the spacer than the inside edge.

    I have the new arm, mounting bolts and shield plate coming and hopefully that will allow allow the whole assembly, including idler, to sit square to each other. Does it seem possible the tank-support part of the frame could be tweaked and causing this?


    barnard -
    When you talk about the bottom belt guide you mean the pin/bolt that sticks out from the frame and isn't visible in this picture? Doesn't seem that this is contacting the belt at all. If you mean that rusted, bent post, I've just replaced that with new hardware. I'll check the bearing (the one mounted in the tank support) for any play.

    Fixdiss -
    The idler alignment looks bad to me too. There's no wobble in the pulley, but the arm is misaligned to the belt and the frame. I've been waiting a week and a half for the arm, hopefully it comes in soon. I replaced that stand-off sleeve and it's hardware and it lines up a little better, but I think not having the new arm still makes the whole thing out of square. I'll try to flatten that shield plate or replace it as well. When you're talking about marking the belt and checking tracking I don't quite understand though.

    Restrorob -
    I think the same, you can see a groove was worn into the stand-off from running that way too. I thought about getting a new belt on there but didn't want to do it until I was fairly sure that I wasn't going to thrash a new belt with some of these misaligned parts. If everything looks good and it still jumps, I'll put a new belt on there.
  7. awdriven

    awdriven LawnSite Member
    Messages: 31

    Oh, and I changed out that old dried-out fuel line and filter right away if anybody noticed in the pictures!
  8. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Messages: 2,613

    Seems to me the idler is being pulled out of alignment by the spring try this
    Once you remove the spring, see if that idler has any wobble type play in it and also check to make sure the hardware it is attached to the frame with is not bent.


    FIXDISS LawnSite Senior Member
    Messages: 445

  10. viper00085

    viper00085 LawnSite Member
    from NC/VA
    Messages: 237

    changing out that what looks to be bent idler arm bracket should fix most of the problem, I would also change out the belt and start with a fresh tight one. Also to fine tune your alignment from the jackshaft pulley to the wheel pulley, there are shim washers behind the wheel hub usually. and you can move them around (front to back and vice versa) to get that aligned properly and stop the belt from walking off the pulleys when moving, specially when pulling the unit in reverse (when we have a seen a few customers units do it most of the time)

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