Tie Rod
A steering component that connects the steering gear or rack to the steering knuckle, transferring steering force to turn the wheels.
A tie rod is a critical component of a vehicle's steering system that links the steering rack or gear assembly to the steering knuckle at each front wheel. When you turn the steering wheel, the steering gear pushes or pulls the tie rods, which in turn push or pull the wheels to steer the vehicle.
Tie rod assemblies are divided into two parts: the inner tie rod (which attaches to the steering rack) and the outer tie rod (which connects to the steering knuckle). The outer tie rod contains a ball-and-socket joint that allows the wheel to move up and down with the suspension and pivot side-to-side for steering. A rubber boot protects this joint from dirt and water.
Over time, the ball joint in the outer tie rod wears down, causing play or looseness in the steering. Symptoms of a worn tie rod include a loose or "sloppy" steering wheel, a squeaking or clunking noise when turning, uneven front tire wear, and the vehicle pulling to one side. A completely broken tie rod will cause a total loss of steering control over that wheel, which is a catastrophic safety hazard.
Because tie rods control wheel direction, replacing them alters the vehicle's suspension angles. A wheel alignment is always required after replacing inner or outer tie rods to restore manufacturer specifications.