Suspension System: Notes
Suspension System
Preliminary Inspection
- 1.
Road test the vehicle.- If any suspension alignment or ride height concerns are present, GO to Symptom Chart - Suspension System below.
- Verify the customer concern by carrying out a road test on a smooth road. If any vibrations are present, GO to Symptom Chart - NVH below.
- 2.
Inspect the tires.- Check the tire pressures with all normal loads in the vehicle and the tires cold. Refer to the VC label.
- Verify that all tires are sized to specification. Refer to the VC label.
- Inspect the tires for incorrect wear and damage. Install new tires as necessary.
- 3.
Inspect the chassis and underbody.- Remove any excessive accumulation of mud, dirt or road deposits from the chassis and underbody.
- Front or rear suspension components
- Suspension fastener(s)
- Incorrect spring usage
- Spring(s)
- Shock absorber(s)
- Strut(s)
- Suspension bushing(s)
- Steering system components
- Subframe
- Wheel bearing and wheel hub(s)
- Tires
- Non-OEM parts or modifications
- 4.
Inspect for aftermarket equipment.- Check for aftermarket changes to the steering, suspension, and wheel and tire components (such as competition or heavy duty). The specifications shown in this service information do not apply to vehicles equipped with aftermarket equipment.
Symptom Chart - Suspension System
Diagnostics in this service information assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Diagnostic Methods
| Condition | Possible Sources | Action |
|---|---|---|
| Vehicle drifts/pulls | Unevenly loaded or overloaded vehicle | GO to Pinpoint Test A |
| Tires/tire pressure | ||
| Alignment is not within specification | ||
| Brake drag | ||
| Steering components | ||
| Subframe misalignment | ||
| Wander | Overloaded, unevenly or incorrectly loaded vehicle | NOTIFY the customer of incorrect vehicle loading. |
| Ball joint(s) | INSPECT the ball joints. REFER to the Ball Joint Inspection component test in this article. | |
| Damaged or missing front strut mount bearing(s) | INSTALL a new front strut mount bearing(s) as necessary. REFER to: Front Strut and Spring Assembly | |
| Loose, worn or damaged front wheel bearing(s) | INSPECT the wheel bearings. INSTALL new wheel bearings as necessary. REFER to: Front Wheel Bearing | |
| Loose, worn or damaged suspension component(s) | INSTALL new suspension component(s) as necessary. Refer to the appropriate Suspension article for the procedure. | |
| Loose suspension fasteners | INSPECT the suspension fasteners. TIGHTEN to specification. Refer to the appropriate Suspension article for the procedure. | |
| Steering components | INSPECT the steering system. INSTALL new components as necessary. Refer to the appropriate Steering System article for the procedure. | |
| Wheel alignment (excessive total front toe out) | ADJUST as necessary. REFER to: Front Toe Adjustment | |
| Front bottoming or riding low | Worn, damaged or incorrect springs | MEASURE the ride height. REFER to: Ride Height Measurement INSTALL new springs as necessary. REFER to: Front Strut and Spring Assembly |
| Worn front strut(s) | INSTALL new struts as necessary. REFER to: Front Strut and Spring Assembly | |
| Abnormal/incorrect tire wear | Incorrect tire pressure (rapid center rib or inner and outer edge wear) | ADJUST the tire pressure. REFER to the VC label. REFER to DIAGNOSIS AND TESTING for further tire wear diagnosis. |
| Incorrect tire rotation intervals | Refer to the appropriate portion of MAINTENANCE SCHEDULES for the procedure. | |
| High-speed cornering Excessive front or rear toe (inner or outer edge wear) Excessive negative or positive camber (inner or outer edge wear) |
REFER to: Wheels and Tires | |
| Front or rear suspension components | INSPECT the front and rear suspension system. REPAIR or INSTALL new suspension components as necessary. Refer to the appropriate Suspension article for the procedure. | |
| Sticky steering, poor returnability | Damaged or worn front strut mount bearing(s) | INSTALL a new front strut mount bearing(s) as necessary. REFER to: Front Strut and Spring Assembly |
| Binding ball joints | REFER to the Ball Joint Inspection component test in this article | |
| Steering components | INSPECT the steering system. INSTALL new components as necessary. Refer to the appropriate Steering System article for the procedure. | |
| Steering wheel off-center | Unequal front or rear toe setting (side-to-side) | CHECK the wheel alignment. REFER to: Front Toe Adjustment |
| Steering components | INSPECT the steering system. INSTALL new components as necessary. Refer to the appropriate Steering System article for the procedure. | |
| Sway or roll | Overloaded, unevenly or incorrectly loaded vehicle | NOTIFY the customer of incorrect vehicle loading. |
| Loose wheel nut(s) | TIGHTEN the wheel nut(s) to specification. REFER to: Specifications | |
| Strut(s) or shock absorber(s) | INSTALL new struts or shock absorbers as necessary. REFER to: Front Strut and Spring Assembly or REFER to: Rear Shock Absorber | |
| Loose stabilizer bracket-to-frame bolts | TIGHTEN the bolts to specification. Refer to the appropriate Suspension article for the procedure. | |
| Worn stabilizer bar bushings or links | INSTALL new stabilizer bar bushings or links as necessary. REFER to: Front Stabilizer Bar Bushing | |
| Damaged or broken stabilizer bar | INSTALL a new stabilizer bar as necessary. REFER to: Front Stabilizer Bar | |
| Worn spring(s) | INSTALL new springs as necessary. REFER to: Front Strut and Spring Assembly or REFER to: Spring | |
| Vehicle leans to one side | Unevenly loaded or overloaded vehicle | NOTIFY the customer of incorrect vehicle loading. |
| Front or rear suspension components | INSPECT the front and rear suspension systems. INSTALL new suspension components as necessary. Refer to the appropriate Suspension article for the procedure. | |
| Incorrect drive axle(s) ride height. Side-to-side lean out of specification | MEASURE the ride height. REFER to: Ride Height Measurement INSPECT the front and rear suspension systems. REPAIR or INSTALL new components as necessary. Refer to the appropriate suspension article for the procedure. |
Symptom Chart - NVH
NVH symptoms should be identified using the diagnostic tools that are available. For a list of these tools, an explanation of their uses and a glossary of common terms, REFER to: Noise, Vibration and Harshness (NVH) . Since it is possible any one of multiple systems may be the cause of a symptom, it may be necessary to use a process of elimination type of diagnostic approach to pinpoint the responsible system. If this is not the causal system for the symptom, REFER to: Noise, Vibration and Harshness (NVH) for the next likely system and continue diagnosis.
| Condition | Possible Sources | Actions |
|---|---|---|
| Squeak or grunt - noise from the suspension | Front or rear suspension components | INSPECT the front or rear suspension. INSTALL new components as necessary. Refer to the appropriate Suspension article for the procedure. |
| Clunk - noise from the front suspension, occurs in and out of turns | Loose front suspension | INSPECT for loose nuts or bolts. TIGHTEN to specifications. Refer to the appropriate Suspension article for the procedure. |
| Clunk - noise from the rear suspension, occurs when shifting from REVERSE to DRIVE | Loose rear suspension components | INSPECT for loose or damaged rear suspension components. REPAIR or INSTALL new components as necessary. Refer to the appropriate Suspension article for the procedure. |
| Click or pop - noise from the front suspension. More noticeable over rough roads or over bumps | Worn or damaged ball joint(s) | CARRY OUT a ball joint inspection. INSTALL new lower arm assembly as necessary. REFER to: Lower Arm |
| Front suspension noise - a squeak, creak or rattle noise. Occurs mostly over bumps or while turning | Front suspension components Loose or damaged front struts, shock absorber(s) or shock absorber bushing(s) Damaged spring or spring mount(s) Damaged or worn control/radius arm bushing(s) Worn or damaged stabilizer bar bushings or link(s) Worn or damaged upper strut mount bearing(s) |
INSPECT the front suspension. INSTALL new components as necessary. Refer to the appropriate Suspension article for the procedure. |
| Rear suspension noise - a squeak, creak or rattle noise. Occurs mostly over bumps or rough roads | Loose or damaged rear shock absorber(s) or shock absorber bushing(s) Damaged spring or spring mount(s) Damaged or worn control arm bushing(s) Worn or damaged stabilizer bar bushing(s) or link(s) |
INSPECT the rear suspension. INSTALL new components as necessary. Refer to the appropriate Suspension article for the procedure. |
| Shudder - occurs during acceleration from a slow speed or stop | Incorrect ride height causing incorrect driveline angle | Refer to the appropriate Driveline article for the procedure. |
| Shimmy | Loose wheel nut(s) | TIGHTEN the nut(s) to specification. REFER to: Specifications |
| Loose front suspension fastener(s) | TIGHTEN the fastener(s) to specification. Refer to the appropriate Suspension article for the procedure. | |
| Loose front wheel bearing(s) | INSPECT the front wheel bearing(s). INSTALL new bearing(s) as necessary. REFER to: Front Wheel Bearing | |
| Strut(s) or shock absorber(s) | INSTALL new struts or shock absorbers as necessary. REFER to: Front Strut and Spring Assembly or REFER to: Rear Shock Absorber | |
| Shimmy - most noticeable on coast/deceleration. Also hard steering condition | Excessive positive caster | INSPECT the front suspension. Refer to the appropriate Suspension article for the procedure. REPAIR or INSTALL new suspension components as necessary. |
| Rough/harsh ride | Incorrect tire pressure | ADJUST the tire pressure. REFER to the VC label. |
| Low ride height | MEASURE the ride height. REFER to: Ride Height Measurement INSTALL new springs as necessary. REFER to: Front Strut and Spring Assembly or REFER to: Spring | |
| Loose, worn or damaged suspension component(s) | INSTALL new suspension component(s) as necessary. Refer to the appropriate Suspension article for the procedure. |