Checking the suspension and steering (BMW 3 Series E46)

Front suspension and steering

1. Raise the front of the car and place it on reliable supports (see appendix: Lifting the vehicle and placing it on supports).

2. Inspect the condition of the ball joint boots and steering gear boots for cracks, abrasions or signs of decomposition. Wear of the boots will lead to leakage of grease, water ingress into the unit and rapid failure.

3. Inspect the hydraulic steering hoses for chafing or signs of decomposition, and the pipe connections for leaks. Also inspect the steering gear boots for pressure leaks, which indicates a faulty internal seal.

4. Grasp the front wheel in a vertical plane (Fig. 7.4) and try to rock it. There may be a small amount of play, but if the movement is noticeable, you need to find out its cause. Continue rocking the wheel and ask an assistant to press the brake pedal at this time. If the play has decreased significantly, this may indicate wear of the wheel hub bearings. If the play remains the same with the pedal pressed, then the hinges or suspension supports are worn.



5. Now grab the wheel on the right and left and try to swing it horizontally again. In this case, the play may also be a consequence of wear of the hub bearings, as well as wear of the steering ball joints. If the inner or outer joint of the steering rod is worn, the play will become quite noticeable.



6. Using a large screwdriver or pry bar, check the suspension bushings by inserting a lever between the part in question and its support point. There should be some play, as the bearings are made of rubber, but significant wear will be evident. Also inspect the rubber bushings for cracks, delamination, and decomposition of the rubber.

7. Lower the wheels to the ground and have an assistant turn the steering wheel left and right about 1/8 of a turn. There should be little or no delay between the steering wheel and the front wheels. If not, carefully inspect the joints as above and, in addition, check the steering column universal joint for wear and the engagement of the steering gear pinion with the rack.

Suspension strut and shock absorber

8. Inspect the shock absorber body for signs of fluid leakage, which may indicate a faulty seal on its rod. If a leak is found, the entire strut should be replaced.

Note: Suspension struts should only be replaced in pairs, i.e. on both sides of the vehicle.

9. The effectiveness of the shock absorbers can be checked as follows. Press on the corner of the car and release it. The car should return to its original position without oscillation or after one-D83 oscillation. Also inspect the upper and lower shock absorber mounts for wear.