Slow..Rider,
Using my definition of bump steer, you would have had to change some steering geometry to create this problem. Just changing the drag link without altering the linear (?) relationship of steering arm and pitman would not create it.
Are you sure something in your retrofit isn't loose or adjusted wrong and you are merely having a tracking problem.
Bump steer is just that, when you front wheels hit a bump, the upward or downward movement of the axle changes the distance from steering arm to pitman arm which either pulls the steering arm or pushes the steering arm which causes the truck to steer right or left...without you turning the wheel.
If the angular plane of the drag link to steering arm and pitman arm isn't flat, a bump will shorten the distance or increase the distance which will tend to drive the wheel one way or the other.
This is how I have always understood it.
Stuart
