wheel shimmy on 777

Discussion in 'Lawn Mowing' started by heavenlydeere, Jul 5, 2005.

  1. heavenlydeere

    heavenlydeere LawnSite Member
    Messages: 109

    i could use some advice on correcting a shimmy problem on my jd 777, at top speed , on hard surfaces , if you hit any bump at all the castors start shimmying quite violently, it does it also if you go from sitting still to full speed and turn at all doing it ! any help would be greatly appreciated!
  2. QualityLawnCare4u

    QualityLawnCare4u LawnSite Gold Member
    Messages: 3,758

    I remember reading about that in my manual on the 737 and 717, I would think the 777 is similar. If I remember correctly, you had to pop the covers off the front casters and remove a cotter pin and tighten the bearing nut. I dont have the book right in front of me, just going from memory here. Will have to get the manual and re-read it to make sure before I look stupid! :rolleyes:
  3. specialtylc

    specialtylc LawnSite Bronze Member
    Messages: 1,656

    You have too much air pressure in the tires or not enough weight on the axle.
  4. QualityLawnCare4u

    QualityLawnCare4u LawnSite Gold Member
    Messages: 3,758

    Yep, that could cause it too.
  5. gl1200a

    gl1200a LawnSite Senior Member
    Messages: 512

    The original posts on this subject explained that the problem was a loose nut that hold the front wheel assembly to the mower. Take the top dust cover off of the assembly and tighten the nut down. Not sure what the reference point is for acceptable torgue values.
  6. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Messages: 11,087

    So listen John Deere guys, do your ZTrac's have tapered roller bearings on the castors like my Lesco does? I actually have the opposite problem. My front castors are too stiff and don't turn freely.

    The reason I asked if the JD has the tapered roller bearings is that to my understanding they need a specified amount of preload for long life. But I think mine have too much. So I was actually thinking about removing the grease caps to take a round or two off the jam nut to free my castors up some more.
  7. fool32696

    fool32696 LawnSite Senior Member
    Messages: 993

    In my experience that condition means that the bearings are bad. May be able to tighten nut, but I'd pull everything apart first and grease it up good.

Share This Page