SA Front Wheel Shimmy

Wed Aug 08, 2007 9:02 am

My SA front-end has developed a shimmy/wobble. I haven't jacked it up yet to see if is the wheel bearings or bushings. It seems to be only the right side but once it gets going look out. :D Can someone point out some other areas that might contribute to the high speed wobble. Are the bushings hard to put in? How about the steering knuckle post being worn at the bushings. Can this be built up and re-machined or do they make oversized bushings?

Mark "GAGoober" Prater

Wed Aug 08, 2007 9:11 am

Take a look at the tie rod ends too.

Wed Aug 08, 2007 7:06 pm

BD is right--tie rod ends can be a big factor--at both ends of both of them. Spindle bushings are probably worn, but are not likely to be a major factor in shimmy as the weight of the tractor tends to take them out of the equation. The sector shaft is another place for slop on the SA--it has a taper with a woodruff key and a slotted nut. If the slotted nut has been allowed to work loose, and/or the thrust washer is badly worn, the boss of the pitman arm may be flopping against the key--considerable wear will happen quickly here.
Place the axle on two jack stands inboard of the front wheels, sit in front of the tractor and wiggle the tires--observing where the slop is--may be in several places--it is additive! Next, move the steering wheel back and forth, looking what moves in what order from that end of the train. Now, just decide where to start!