Jeep Parts > Technical Articles > Bump Steer

Bump Steer

Bump steer is one of those mildly dangerous annoyances which come from second-guessing Jeep engineers. This would be a good excuse for an article about why not to modify a Jeep, but that's not realistic. The only reason to own a Jeep is to modify it, so let's just concentrate on fixing the problems which inevitably result from Jeep ownership. Bump steer is the directional change in the front wheels caused by suspension movement instead of your steering system. Okay, now in English: bump steer is when the bumps are steering your Jeep and you aren't. Naturally, you'll want to fix that quickly.

The ultimate cause of bump steer can usually be traced to lifting a vehicle without adjusting the drag link and track bar properly. Under factory-created circumstances, the track bar and the drag link are parallel to each other. Lifting the vehicle changes that geometry. If you hit a bump, your suspension moves upward. If those two bars are no longer parallel, the upward movement of the suspension pushes or pulls the drag link sideways. One side of your axle will compress, causing the Jeep to steer to that side as soon as the suspension comes back down.

As with many Jeep maladies, the best fix is simply prevention. If you are planning to lift your rig, get a lift kit with a trac-bar relocation bracket which enables you to reposition the track bar so it remains parallel to the drag link. Some lift kit manufacturers recommend using a dropped Pitman arm as well, although this could vary in effectiveness depending on your model and year. If your vehicle has already been lifted and you are beginning to experience bump steer, you have some re-engineering to do. In the end your track bar length and angle need to match those of the drag link, and this may require you to relocate the steering stabilizer as well as the anti-sway bar linkage.

Your bump steer might not completely disappear as a result of this further modification. The suspension setting, the weight of the passengers and the placement of your cargo will all change the way your steering works. Also, since no two Jeeps are identical, even before the modifications, your vehicle could need more tweaking than most. If all else fails, go through your lift kit instructions and - yes - the owner's manual, and find out what you didn't change that you should have.