Jeepin Al wrote:
bump steer is all upper control arm and the angle of it. as the suspension is cycled, the ball joint moves further outward from the spring. The top of the spindle is pushed outward, pulling on the tie rod end, it wants to pull the tie rod outward also, it doesn't, the tie rod stays essentially static, but the forces from the spindle outward motion pulls the tires inward pivoting around the tie rod end causing a toe in condition. Now that everyone is confused I need to go back to work.
Al
Weird...I am not envisioning that completely. What I see is with the sever droop of the tie rod it makes it essentially shorter at rest. As the wheel is compressed like in a highway dip that rod gets longer pushing the tire out causing a toe out condition and if on just one wheel would actually steer the vehicle to the left on a drivers dip and right on a passenger side dip.
I do see how the UCA would also get longer in the same dip/scenario but as it and the tie rod travel the same arc the wheel would toe out and not in.
Seems to me what is needed for good highway manners is to have the UCA and tie rod horizontal at rest which would require a custom spindle but should the LCA pivot also be dropped for correction?