Mule drive Idler question

Discussion in 'eXmark' started by Runner, May 8, 2002.

  1. Runner

    Runner LawnSite Fanatic
    Messages: 13,497

    I have a problem with my idler pulley on my Lazer. When I kick my blades in, (at low rpm's) the rear idler to the mule drive belt moves down , then comes up and CLACKS against the chassis. This is hitting hard, and has even bent the edge of the idler pulley. As I looked, there is no adjustment for that spring or pulley itself. What can I do to avoid this? I realize there is a tension adjustment for that belt, but it seems as though the slack is in the spring, itself. Have these springs been known to wear out, possibly? Any help is greatly appreciated. Also, if there are any other Lazer users that have experienced this, please let me know. Thanks.
  2. eXmark

    eXmark Manufacturer / Sponsor
    Messages: 4,258


    It is possible that you've got a weak spring however there are a couple of other things I would check first.

    I'm sure you've already done this but for those who are not aware of it, -adjust the mule drive belt with the fixed idler on the other side. The adjustment only takes a minute and isn't that difficult once you understand it. This is one item that is explained fairly well in the operators manual but I need practice typing.

    The mule drive adjustment can be checked by looking at the two "sight holes" in the sheet metal just ahead of the "L" bracket on the LH side of the machine. The bolt that holds the idler pulley to the spring-loaded arm should lie between these two “sight holes”, preferably toward the top. To make the mule drive adjustment place a 9/16" wrench on the bolt that holds the idler pulley to the idler arm and lift. This releases the tension on the belt. Block the wrench up, hold it with your foot or have an assistant hold it. With the belt tension removed take two 9/16" wrenches and loosen the nut/bolt on the RH idler or fixed idler. This idler is not spring loaded but is in a slotted hole. Lower the fixed idler in the slot and re-tighten. Release the spring-loaded idler and verify the correct setting.

    If all is O.K. here then you should look at the idler for the deck. Upon engagement, all of the shock that is applied to the mule drive and deck drive belts should be divided equally between the spring loaded deck idler and the mule drive idler. If the deck idler is not functioning properly then the mule drive must absorb all of it. When this happens the mule drive spring may be over taxed and allow the idler pulley to impact with the frame/engine deck.

    To inspect the deck drive idler remove the trim side belt shield. Grab a hold of the belt on both sides just ahead of the trim side spindle pulley. Pull the belt toward you then lift it off of the pulley and slowly release the belt. There should be no tension on the idler arm with the belt removed from one pulley. You should now be able to simply pull the idler spring off with almost no resistance. Literally grab it and lift it off. Pivot the idler arm back and forth several times to make sure it is pivoting completely freely. It should almost feel a little sloppy. If it does not pivot freely unbolt it, clean it up with some emery cloth or fine sand paper, re-grease it and re-install it. This same procedure can also be done to the mule drive idler before you adjust it if you like; however it is less likely to be required.

    The deck drive idler can be especially susceptible to corrosion because it is mounted vertically and often operators will wash under the foot well of the deck periodically to ensure it is clean. I'm not sure why they wash under there but they do just the same. This can also happen if they are not washing. The key to ensuring the idler continues to pivot freely is remove the belt shield once per month and remove the belt tension. Grease the pivot point with your grease gun while the arm is in this "no load" position. Then grease it weekly while in the normal load position. Incidentally it also makes your belts last much longer.

    Also make sure your engaging at 1/2 throttle. I've seen some cases where engaging at idle for one reason or another can cause the mule drive idler to swing excessively.

    If all else fails, replace the spring. More often than not however this problem relates back to the mule drive adjustment, mule drive idler pivot or the deck idler pivot.

    Let me know what you find out. You never know we might have something new to learn here.



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