SUSPENSION DIAGNOSIS

Transcription

1 SECTION 2A SUSPENSION DIAGNOSIS TABLE OF CONTENTS Diagnosis... 2A-2 General Diagnosis... 2A-2 Hub and Bearing... 2A-7

2 2A-2 SUSPENSION DIAGNOSIS DIAGNOSIS GENERAL DIAGNOSIS Problems in the steering, the suspension, the tires, and the wheels involve several systems. Consider all systems when diagnosing a complaint. Some problems, such as abnormal or excessive tire wear and scuffed tires, may be the result of hard driving. Always road test the vehicle first. If possible, do this road test with the customer. Proceed with the following preliminary checks. Correct any substandard conditions. Preliminary Inspect the tires for improper pressure and uneven wear. Inspect the joint from the steering column to the steering gear for loose connections or wear. Inspect the front and the rear suspension, the steering gear, and the linkage for loose or damaged parts. Inspect for out-of-round tires. Inspect for out-of-balance tires, bent wheels, and worn or loose wheel bearings. Check the power steering pump serpentine belt tension. Inspect the power steering system for leaks. Also, check the power steering fluid level. Inflate the tires to the proper pressure. Tighten the intermediate shaft pinch bolts. Replace the intermediate shaft, as needed. Tighten the front and the rear suspension. Tighten the steering gear mounting bracket bolts. Tighten the intermediate shaft pinch bolts. Replace the front and the rear suspension, as needed. Replace the steering gear, as needed. Replace the intermediate shaft, as needed. Perform a free runout test. Match-mount the tires. Balance the wheels. Replace the wheels. Replace the wheel bearings. Tighten the power steering pump serpentine belt. Repair any leaks. Perform a power steering system test. Add power steering fluid, as needed. Car Lead/Pull Inspect for mismatched or uneven tires. Inspect for a radial tire lateral force. Check the front-wheel alignment. Inspect for an off-center steering gear. Inspect for front-brake dragging. Replace the tires. Check the wheel alignment. Switch the tire and the wheel assemblies. Replace the tires, as needed. Align the front wheels. Reseat the pinion valve assembly. Replace the pinion valve assembly, as needed. Adjust the front brakes. Scuffed Tires Inspect for incorrect toe on the front and the rear wheels. Inspect for a twisted or a bent suspension arm. Adjust the toe on the front and the rear wheels. Replace the suspension arm.

3 Abnormal or Excessive Tire Wear SUSPENSION DIAGNOSIS 2A-3 Check the front-wheel and the rear-wheel alignment. Inspect for excessive toe on the front and the rear wheels. Inspect for out-of-balance tires. Check for a failure to rotate tires. Inspect for low tire inflation. Align the front and the rear wheels. Adjust the toe on the front and the rear wheels. Balance the tires. Rotate the tires. Replace the tires, as needed. Inflate the tires to the proper pressure. Wheel Tramp Inspect for an out-of-balance tire or wheel. Balance the tire or the wheel. Shimmy, Shake, or Vibration Inspect for an out-of-balance tire or wheel. Inspect for excessive wheel hub runout. Inspect for excessive brake rotor imbalance. Inspect for worn tie rod ends. Inspect for wheel trim imbalance. Inspect for a worn lower ball joint. Inspect for excessive wheel runout. Inspect for excessive loaded radial runout on the tire and the wheel assembly. Balance the tire or the wheel. Measure the hub flange runout. Replace the hub, as needed. Adjust the brakes. Replace the brake rotor, as needed. Replace the outer tie rods. Balance the wheel. Replace the lower ball joint. Measure the wheel runout. Replace the wheel, as needed. Match-mount the tire and the wheel assembly. Hard Steering Check the hydraulic system. Test the power steering system pressure with a gauge. Inspect for binding or catching in the steering gear. Inspect for a loose steering gear mounting. Replace the seals and the hoses, as needed. Lubricate the steering gear. Repair or replace the steering gear, as needed. Tighten the steering gear mounting bracket nuts and the bolts.

4 2A-4 SUSPENSION DIAGNOSIS Too Much Playin Steering Inspect for worn or loose front wheel bearings. Inspect for a loose steering gear mounting. Inspect the joint from the column to the steering gear for loose connections or wear. Replace the front wheel bearings. Tighten the steering gear mounting bracket nuts and the bolts. Tighten the intermediate shaft pinch bolts. Replace the intermediate shaft, as needed. Poor Returnability Inspect for lack of lubrication of the ball joints and the tie rod ends. Inspect for binding in the ball joints. Inspect for binding in the steering column. Check the front-wheel alignment. Inspect for a sticking valve. Inspect for binding in the intermediate shaft on the steering gear. Replace the ball joints and the outer tie rods. Replace the ball joint. Lubricate the steering column. Replace the steering column as needed. Align the front wheels. Lubricate the pinion valve assembly. Replace the pinion valve assembly, as needed. Replace the intermediate shaft. Abnormal Noise, Front Suspension Inspect for a lack of lubrication of the ball joints and the tie rod ends. Inspect for damaged suspension components. Inspect for worn control arm bushings or tie rod ends. Inspect for a loose stabilizer link. Inspect for loose wheel nuts. Inspect for loose suspension bolts or nuts. Replace the ball joints and the outer tie rods. Replace the damaged suspension components. Replace the control arm bushings or the tie rods. Tighten the stabilizer link. Tighten the wheel nuts. Tighten the suspension bolts or the nuts. Abnormal or Excessive Tire Wear Inspect for mismatched or uneven tires. Inspect for lack of lubrication of the ball joints and the tie rod ends. Inspect for a loose stabilizer link. Check the front-wheel and the rear-wheel alignment. Replace the tires. Replace the ball joints and the outer tie rods. Tighten the stabilizer link. Align the front and the rear wheels.

5 Erratic Steering when Braking SUSPENSION DIAGNOSIS 2A-5 Inspect for worn or loose front wheel bearings. Inspect for a leaking wheel cylinder or caliper. Inspect for warped rotors. Inspect for an incorrect or an uneven caster. Replace the front wheel bearings. Replace the wheel cylinder or the caliper. Replace the rotors. If the caster is beyond specifications, check the frame and repair it, as needed. Low or Uneven Trim Height Inspect for an incorrect or weak spring. Ride Too Soft Ride Too Harsh Inspect for incorrect dampeners. Inspect for an incorrect spring. Body Leans or Sways in Corners Inspect for a loose stabilizer link. Tighten the stabilizer link. Suspension Bottoms

6 2A-6 SUSPENSION DIAGNOSIS Steering Wheel Kickback Inspect for air in the power steering system. Inspect for a loose steering gear mounting. Inspect the joint from the column to the steering gear for loose connections or wear. Inspect for loose tie rod ends. Inspect for loose or worn front wheel bearings. Purge the power steering system of air. Tighten the steering gear mounting bracket nuts and the bolts. Tighten the intermediate shaft pinch bolts. Replace the intermediate shaft, as needed. Tighten the tie rod ends. Replace the outer tie rods, as needed. Replace the front wheel bearings. Steering Wheel Surges or Jerks Check the hydraulic system. Test the power steering system pressure with a gauge. Inspect for a sluggish steering gear valve. Inspect for a loose power steering pump serpentine belt. Replace the seals and the hoses, as needed. Clean the pinion valve assembly. Replace the pinion valve assembly, as needed. Adjust the power steering pump serpentine belt. Cupped Tires Check the front-wheel and the rear-wheel alignment. Inspect for worn or loose wheel bearings. Inspect for excessive tire or wheel runout. Inspect for a worn ball joint. Align the front and the rear wheels. Replace the wheel bearings. Match-mount the tires. Replace the tires, as needed. Replace the wheels, as needed. Replace the ball joint.

7 SUSPENSION DIAGNOSIS 2A-7 KAA2A010 HUB AND BEARING Perform the following test to check for looseness in the hub and bearing assembly: 1. Raise and suitably support the vehicle. 2. Remove the rear wheel. Refer to Section 2E, Tires and Wheels. 3. Remove the caliper and the disc brake rotor. Refer to Section 4E, Rear Disc Brakes. 4. Mount a dial indicator set with a magnetic base to a stationary part of the vehicle. 5. Push and pull the wheel hub by hand. If the wheel hub movement exceeds 0.03 mm (0.001 inch), replace the hub and bearing assembly. Refer to Section 2D, Rear Suspension. 6. Install the caliper and the disc brake rotor. Refer to Section 4E, Rear Disc Brakes. 7. Install the rear wheel. Refer to Section 2E, Tires and Wheels. 8. Lower the vehicle.