I havent drove it yet at high speeds but i was told that it would dart around. I moved it around the shop and it steered ok. Has anyone had any experience or could tell me were to start? The front end tierods and bearing are in good shape.
Don't know the specification, but ask a dealer or find a manual, make sure the steer tires are set at the correct toe-in, and if the problem shows up, try a bit more toe in at the leading edge. In a truck I would say caster, but I have no idea if tractors have any let alone an adjustment.
Try the John Deere section: http://www.yesterdaystractors.com/