The only ball joints that can be replaced on a BMW are the lower ball joints. If the upper ball joints need serviced, you will have to change the entire control arm. To complete this project, you will need a special tool to free the ball joint from the lower control arm. There is no other way to get it out without causing damage to the lower control arm. However, the tool required is not very expensive, so it is worth buying the tool, rather than paying high labor costs to have the job done professionally.
Park the car on a level surface and place the wheel chocks behind the rear wheels.
Jack the car up with an automobile jack and place a jack stand under the frame near the jacking point, for added safety. Raise the jack stand as close to the frame as possible.
Remove the wheel with a lug wrench.
Use a socket and ratchet to disconnect the rear control arm bushing bracket where it connects to the body.
Remove the nut and disconnect the front stabilizer from the control arm with a socket and ratchet. Remove the nut that connects the control arm to the cross member with a ratchet and socket. Knock the stud out of the cross member with a rubber mallet.
Use a socket and ratchet to remove the bolts that connect the hub to the struts.
Make a mark on the lower control arm where the ball joint connects to it, for proper alignment of the new ball joint. Remove the cotter pin and nut from the ball joint. Use the special ball joint tool to press the ball joint out of the control arm.
Place the new ball joint in the control arm assembly and line it up according to the mark you made previously. Use the special ball joint tool to press the new ball joint into place on the control arm. Install the nut using the proper socket and ratchet and then put the cotter pin into place to lock the nut.
Reattach the hub to the struts and tighten the bolts with a socket and ratchet. Reconnect the front stabilizer to the control arm and tighten it with a socket and ratchet.
Reinstall the stud and reattach the control arm to the cross member. Tighten it up with a ratchet and socket.
Reattach the rear control arm to its position on the body and then tighten it up.
Reattach the wheel to the car and remove the jack stand. Lower the car to the ground and repeat the process on the other side of the car.
