For those that do not know how to solve this problem, Bumpsteer is sometimes caused when you lower your vehicle and when doing so causes your Tie rods to be subject to an unwanted angle. For those that are not familiar with the term bumpsteer it is exactly as it reads. When your vehicle hits a bump it in the road your steering wheel vibirates or moves, not only is this harsh on your front suspension componets but it is also dangerous! This can be solved by relocating your tie rods or "flipping" them where they bolt to the spindle.
The tie rods do have a cone shape seated design so its not possible to just unbolt and flip them, Luckily there are some inserts available that can be installed that will allow you to flip the rods. The hole in the spindle where the tie rod connects will have to be drilled to a larger hole because remember that the ball joint on the tie rod is tapered which means that the hole is larger on top than it is at the bottom. Once the hole is enlarged you now tap the hole with the required Tap for the inserts to be installed. Now you can screw the tapered inserts in which will now make the hole larger on the bottom which allows for the tie rod to be flipped, which solves your bumpsteer problem. The only thing that you will have to do is adjust your toe in and out because of the tie rods new location.

BTW i have inserts avaliable for 1999-2006 1/2 ton silverado 2wd pickups
or any model that uses the same spindle.
for info on these look in the parts classified section.