The Rusty's JK drop pitman offers 1.5 inches of drop and is recommended for lifts over 4 inches tall. This Drop Pitman Arm is specifically for power steering applications only.
General Information: Your vehicle's steering linkage connects the steering box (mounted on the frame) to the steering knuckles (attached to the axle). As a vehicle is lifted, the increased distance between the axles and the frame causes the steering linkage operating angle to change. Once the vehicle is lifted past a certain point, the steering linkage angle must be adjusted (corrected) in order to work properly. This is especially important for vehicles equipped with a track bar (the suspension link that locates the front axle side-to-side). If left uncorrected, improper steering angles can lead to all sorts of bad steering and handling traits, including bump-steer and "death wobble," and in extreme cases can lead to steering bind and failure. Losing your ability to steer is a very bad thing whether you're on the street or on the trail!
As the name implies, the pitman arm is the "arm" that connects the drag link (the link that runs from the steering box to the tie rod or passenger side knuckle) to the steering box output (sector) shaft. A drop pitman arm is roughly S-shaped and lowers the drag link's attachment point in relation to the box, causing the drag link's operating angle to be reduced back to it's stock operating angle (or at least very close to it). A drop pitman arm also allows the drag link's operating angle to remain "in phase" with the track bar, which is important for maintaining good handling characteristics.
A special tool is required to remove the pitman arm from the steering sector shaft. This tool can be rented or purchased at most auto-parts stores.