When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Bump steer is caused by a difference in geometry between the suspension travel and steering linkage travel, or worn parts. If you're compressing your suspension that much on highway driving, you probably need new shocks, not longer bumps. Would have probably cost less than those things that are now going to mask the real issue.
For completeness, I’ll fill in the holes. I converted this truck to 4wd 8 years ago using a rollover 2006 as a donor. Dude put the front shock towers “where we had to” and since there were no bolt holes there, he welded them on. Turns out they aren’t in the right place which causes the springs to be overly compressed and thus “bouncy”. Yes, we could have shortened the springs and likely fixed it. Unfortunately, nobody suggested that at the time and we leveled it by adding a leaf in the rear. That would have been fine, except not only are the shock towers too low, they’re also too far back, leaving a curve in the spring. We’ve overcome most of the geometry issues with various modifications, but the real fix would be to cut off the shock towers and move them. That would probably destroy them and we’d need new ones. Plus we may find out that he had, in fact, put them “where we had to” and thus we’re right back in the same boat $1000+ later. I just put 52k miles on a set of AT tires and got even wear on them. I say that to say it’s aligned fine and has worked well for 116k miles since conversion. I’m just trying to get rid of the front end “wave” from the springs and the small amount of bump steer that goes along with it. The shocks control that fine at lower speeds but not at 75 mph. This idea may or may not work.