Control Arm: Description and Operation
LOWER CONTROL ARMDESCRIPTION
There is one lower control arm on each side of the vehicle. Each lower control arm is a stamped steel unit using rubber isolated pivot bushings to isolate it from the front suspension crossmember and frame of the vehicle. The rear bushing can be serviced separately.
The front of the lower control arm is bolted to the front crossmember using a bolt through the center of the rubber pivot bushing. The rear of the lower control arm is mounted to both the front crossmember and the frame rail of the vehicle using a thru-bolt. The thru-bolt goes through both the crossmember and rear lower control arm bushing, threading directly into a caged nut in the frame rail of the vehicle.
The left and right lower control arms are interconnected through a linked rubber isolated stabilizer bar.
The outboard end of each lower control arm connects to the steering knuckle using a ball joint.
The lower control arm connects to the steering knuckle through a ball joint mounted at the outboard end of the arm. The ball joint is pressed into the lower control arm and has a non-tapered stud with a notch for steering knuckle pinch bolt clearance. The ball joint stud is clamped and locked to the steering knuckle lower leg using a pinch bolt.
The ball joint is lubricated for life during the manufacturing process. Once lubricated for life, the grease fitting head is snapped off by the manufacturer. This is done to eliminate the possibility of lubrication later in the ball joints life thus damaging the non-vented ball joint seal boot.
The ball joint used on this vehicle is replaceable and can be serviced as a separate component of the lower control arm.
OPERATION
The lower control arm supports the lower end of the steering knuckle and allows for the up and down movement of the suspension during the jounce and rebound travel. The lower control arm ball joint connects the arm to the steering knuckle.
The ball joint is a pivotal joint on the lower control arm that allows the knuckle to move up and down, and turn with ease.