22.16.
Suspension Service
Suspension problems normally include failed shock absorbers, sagging springs, worn out suspension bushings, and worn ball joints. In addition, the tie rod ends wear and become loose to the extent that the parts fall apart even when the automobile is in use, thereby causing accident. Preventive maintenance is the best insurance against suspension breakdown on the road. Routine maintenance of the suspension is limited to lubrication of the ball joints, a through visual inspection of the suspension parts, and checking of steering linkages.The schedule for ball joint lubrication varies with different manufactures. In some automobiles, it is after 6440 km running, in others it is after 24,140 km or each year and in some others it is after 48,280 km or every other year. It is a common practice to lubricate the steering linkage when the ball joints are lubricated. A hand grease-gun is recommended to grease a joint so that the joint can be filled with grease slowly to prevent damage to the joint seal. Grease should be put into the joint until the seal swells slightly and it is to be noted that excess grease may break the seal.Inspection of the suspension starts with a visual observation of the way the automobile stands on a level surface. Sagging indicates spring weakness. Service manuals provide specifications for the location and distance to be used in measuring the suspension height. In most torsion bar systems, the height can be adjusted at one end of the torsion bar. Coil and leaf springs are not adjustable. It is recommended to replace the weak spring, preferably on both sides at the same time. Suspension height is checked and corrected before the front wheels are aligned. Ball joints gradually wear with use. When their wear becomes excessive, they are replaced. Shock absorber failure, other than breakage, is the oil leakage and the continued oscillations after the automobile is bounced and released. Shock absorber replacement is a simple job. Any repair of the suspension that affects the height of the automobile above the floor or any replacement of the suspension bushings should be followed by a front end alignment.
