Note. Suspension and steering components should be checked regularly as wear or damage can shorten tire life, reduce vehicle handling and increase fuel consumption. Detailed illustrative material is also presented in Chapter Suspension and steering.
Wheels on the ground checks
1. Park the car on a flat horizontal area, if possible with a hard surface, turn the front wheels into a straight line position. Lightly tug the steering wheel in both directions - an excessive amount of play that occurs indicates possible wear on the wheel bearings, the collars of the hinges of the main and intermediate shafts of the steering column, the steering knuckle bearings (all-wheel drive models), or tie rod ends. There is also the possibility of misalignment or damage to rack and pinion components (see chapter Suspension and steering).
2. Worn or damaged suspension or steering components can also be indicated by symptoms such as excessive vehicle rocking when driving on rough roads or while cornering, steering wheel jamming, etc.
3. To assess the condition of the shock absorbers, press down one of the corners of the car. When the corner is released, the body should return to its original position, making no more than one or two oscillations. Listen for squeaks and other extraneous noises emitted by the suspension during oscillatory movements of the body. See chapter for details Suspension and steering. Excessive rocking of the body when the corner is released, as well as the refusal to return it to its original position, indicate the need to replace the shock absorbers. Proceeding in a similar manner, check each of the four shock absorbers one by one.
Checks made with the wheels off the ground
1. Jack up the car and put it on stands.
2. Check wheel treads for signs of uneven wear (see Section Checking the condition of tires and their inflation pressure), evaluate the tire inflation pressure.
3. Assess the condition of the cardan joints of the steering column. Check the protective covers of the steering gear and drive shafts for signs of grease leaks. Check up reliability of landing of tips of steering draughts. Check the condition of the components and the reliability of tightening their fasteners. Assess the degree of wear of the rubber components of the suspension and steering gear. Have an assistant turn the steering wheel and visually assess the amount of steering play. Try to identify the cause of the slack, make the necessary remedial repairs, or replace the defective components.
4. Manually rotating the front wheels, try to determine the condition of the wheel bearings by ear, make sure there is no play when the wheels rotate. Grab the wheel at the 12 and 6 o'clock points and pull it in the axial plane - the presence of any noticeable free play indicates a weakening of the wheel bearing preload. If necessary, disassemble the hubs to visually assess the condition of the bearings and pack them with fresh grease. Complete information on the design of hub assemblies and wheel bearings for all-wheel drive models is given in Chapter Suspension and steering.
5. Prying the components with a pry bar, evaluate the condition of the bearings of the steering knuckle assemblies. If play is detected, the bearings should be subjected to a more detailed study, replaced or filled with fresh grease.
6. Assess the degree of wear of the universal joints and sliding couplings of the cardan shafts (see chapter Clutch and transmission line).
7. Inspect the surfaces of the differential and transfer case housings for signs of leak development.