What is the most likely cause of bump steer?

The cause of bump steer primarily involves the steering mechanism not following the intended path relative to the suspension's movement, leading to a vehicle's steering input becoming inconsistent with the road's surface. Worn or oil-soaked rack bushings impact this connection directly by allowing excessive movement within the steering rack. When these bushings degrade, they no longer secure the rack firmly, leading to misalignment and undesired toe changes during suspension travel, which is a primary factor in bump steer.

Proper functioning of the rack bushings is critical because they serve to dampen vibrations and maintain the steering rack’s position. If they become worn or soaked in oil, they can lead to instability in the steering system, which results in the unpredictable steering behavior characteristic of bump steer. Understanding this connection helps technicians focus on areas within the steering and suspension system that require maintenance to ensure vehicle safety and performance.