How to Replace the Control Arm & Bushings on a 1998 BMW 318i

The 1998 BMW 318i came with a 1.9-liter four-cylinder engine and a five-speed manual transmission. The lower control arm on your BMW provides the lower pivot points for the steering and suspension systems. Anytime you replace the lower control arm it will come with new bushings and ball joints pre-installed from the factory. Replacing either front control arm is an in-depth process, but is well within the realm of the home mechanic.

Instructions

Park the vehicle on a level surface and set the parking brake. Loosen the wheel bolts on the wheel to be serviced with a lug wrench. Lift the front of the vehicle into the air with a floor jack and place jack stands under the front sub-frame. Lower the vehicle until it rests securely on the jack stands.

Remove the wheel bolts followed by the wheel and set them aside. Remove the nut securing the sway bar link to the control arm with a socket and ratchet. Install a single wheel bolt to the hole on the top and tighten it snug. Wrap mechanics wire around the coil spring and down around the wheel bolt so that the suspension can support the wheel hub and bearing.

Loosen the outer ball joint nut with a wrench until it contacts the bottom of the strut cartridge. Remove the lower strut to knuckle mounting bolts with a socket and ratchet. Remove the strut clamp bolt and nut with a socket and ratchet.

Position the strut assembly back enough to access the lower ball joint nut and remove the ball joint nut. Install a ball joint separator between the control arm and steering knuckle. Tighten the separator push bolt until the ball joint separates from the steering knuckle.

Loosen and remove the Front most sub-frame to control arm mounting bolts with a socket and ratchet. Follow the opposite leg of the control arm to the rear ball joint at the sub-frame. Loosen and remove the rear ball joint nut. Strike the ball joint stud with a rubber mallet to separate the ball joint. Rotate the control arm on the front pivot point and pull it out of its mounting location. Discard the old control arm.

Clean all tapped holes in the sub frame and steering knuckle with a small wire brush and penetrating oil. Inspect all removed bolts and replace as necessary. Discard the lock nuts for the rear ball joint and the strut clamp. Discard the two lower strut mounting bolts.

Slide the front of the control arm into its hole in the sub-frame. Install the two mounting bolts hand tight. Rotate the control arm and guide the rear ball joint stud into the hole on the sub-frame. Install a new rear ball joint nut hand tight. Guide the lower ball joint into the steering knuckle and install a new nut hand tight.

Tighten the front most control arm mounting bolts to 64 foot-pounds with a torque wrench. Tighten the rear ball joint nut to 72 foot-pounds and the lower ball joint nut to 88 foot-pounds. Install the strut clamp nut and bolt with a single washer on each side. Tighten the clamp nut and bolt to 96 foot-pounds. Install the lower strut mounting bolts and tighten 18foot-pounds foot-pounds if 18 mm in diameter and 25 foot-pounds if 21 mm in diameter.

Place the stabilizer link and bracket onto the control arm and install the securing nut. Tighten the nut to 57 foot-pounds. Remove the mechanics wire and wheel bolt. Install the wheel to the vehicle and install the wheel bolts hand tight.

Lift the front of the vehicle off the jack stands and remove the jack stands from under the vehicle. Lower the vehicle to the ground. Tighten the wheel bolts to 88 foot-pounds in a crisscross pattern. Drive the vehicle to a local repair shop to have the front end alignment checked and adjusted as necessary.