tie rod ends
The tie-rod end is meant to turn wheel thru the whole suspension's travel. So lowering the car would have no affect on it.
When you lower the car, you change the angle at which the tie rod attaches to the knuckle.
Because the rack is a fixed point and the front suspension moves up and down, the tie rod travels in an arc.
After lowering, this geometry is offset somewhat so that the toe is adversely affected. Hence the need for an alignment.
The arc effectively shortens and lengthens the distance between the rack and the knuckle by probably 1/4".
As you roll through a corner, the body leans and compresses one side and unloads the other side of the front suspension.
The tie rod distance changes and induces a phenomenon called "bump steer", a dissimilar change is effective tow as the front suspension compresses and rebounds on opposite sides.
You might have one side actually toeing out while the other side is toeing in, giving you either more (or less depending upon the geometry) effective steering input.
And depending upon the geometry, this could either be a bad thing or a good thing.
It's not so much of an issue on our cars because of the limited suspension travel, unless of course you are competing. But the guys who have monster lifts on their 4x4s have some SERIOUS bump steer problems.


