Diagnosis and Testing - Suspension System

Preliminary Inspection

1. 1
   Road test the vehicle.
   

   • If any suspension alignment or ride height concerns exist, REFER to the Symptom Chart: Suspension System.

   • Verify the customer concern by road testing on a smooth road. If any vibrations are present, REFER to the Symptom Chart: NVH.
2. 2
   Inspect the tires.
   

   • Check the tire pressures at all normal vehicle loads and on cold tires. REFER to the VC label.

   • Make sure all tire sizes match the specification. REFER to the VC label.

   • Inspect the tires for uneven wear and damage. INSTALL new tires as necessary.
3. 3
   Inspect the chassis and underbody.
   

   • Remove excessive accumulations of dirt, mud or road debris from the chassis and underbody.

   • Front or rear suspension components.

   • Suspension mount(s).

   • Improperly seated spring(s).

   • Shock absorber(s).

   • Struts.

   • Suspension bushing(s).

   • Steering system components.

   • Wheel bearing and wheel hub.
4. 4
   Check aftermarket accessories.
   

   • Check for aftermarket modifications to the steering, suspension, wheel and tire components (such as competition or heavy duty). The specifications provided in this manual do not apply to vehicles equipped with aftermarket accessories.

Symptom Chart: Suspension System

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

• If the cause of the observed or recorded condition is found, correct the cause (if possible) before proceeding to the next step.
• If the concern is not visually evident, REFER to the Symptom Chart or REFER to the NVH Symptom Chart.

Symptom Chart: NVH

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

NVH symptoms must be identified using the available diagnostic tools. For a list of these tools, an explanation of their use, and a glossary of common terms, REFER to: Noise, Vibration and Harshness (NVH) (100-04 Noise, Vibration and Harshness, Diagnosis and Testing).
Since any one of several systems may be the cause of the symptom, it may be necessary to use a process of elimination type diagnostic approach to determine the responsible system. If it is not the causal system of the symptom, REFER to: Noise, Vibration and Harshness (NVH) (100-04 Noise, Vibration and Harshness, Diagnosis and Testing) for the next probable system and continue diagnosis.

Additional diagnosis may be required to further isolate the concern. An electronic listening tool such as Chassis Ear® can be used. Follow the tool manufacturer's instructions and the possible sources listed in the following NVH chart to determine the connection points.

Pinpoint Tests

Diagnostic Overview

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

Component Tests

Ball Joint Inspection

1. 1
   Before checking the ball joints for wear, check the wheel bearings. If necessary, install a new wheel bearing.
   REFER TO: Front Wheel Bearing and Hub (204-01A Front Suspension - RWD, Removal and Installation).
   REFER TO: Front Wheel Bearing and Hub (204-01B Front Suspension - AWD, Removal and Installation).
2. 2
   Raise and support the vehicle by the frame so the wheels hang in their natural position.
   REFER TO: Lifting and Jacking - Overview (100-02 Jacking and Lifting, Description and Operation).
3. 3
   Inspect the ball joint and ball joint dust boot for damage.
   

   • If the ball joint or ball joint boot is damaged, install a new lower arm as necessary.
     REFER TO: Front Lower Arm (204-01A Front Suspension - RWD, Removal and Installation).
     REFER TO: Front Lower Arm (204-01B Front Suspension - AWD, Removal and Installation).
     REFER TO: Rear Lower Arm (204-01A Front Suspension - RWD, Removal and Installation).
     REFER TO: Rear Lower Arm (204-01B Front Suspension - AWD, Removal and Installation).
     REFER TO: Lower Arm (204-02 Rear Suspension, Removal and Installation).
4. 4

   NOTICE: Do not use any tools or equipment to move the wheel and tire assembly or suspension components when checking for relative movement. Suspension damage may occur. Using tools or equipment will also create relative movement that may not be present when hand force is used. Relative movement must be measured using hand force only.

   Inspect the ball joint for relative movement by alternately pulling down and pushing up on the lower control arm by hand. Note any relative vertical movement between the steering knuckle and the lower control arm at the lower ball joint.
   

   • If no relative movement is felt or seen, the ball joint is good. Do not install a new lower control arm.

   • If relative movement is detected, go to step 5.
5. 5
   To measure ball joint deflection, attach a suitable dial indicator with a flexible lever between the lower control arm and the steering knuckle or ball joint stud.

6. Measure the ball joint deflection while an assistant manually pushes the lower control arm up and down.
   
   • If the deflection exceeds specification, install a new lower arm.
     REFER TO: Front Lower Arm (204-01A Front Suspension - RWD, Removal and Installation).
     REFER TO: Front Lower Arm (204-01B Front Suspension - AWD, Removal and Installation).
     REFER TO: Rear Lower Arm (204-01A Front Suspension - RWD, Removal and Installation).
     REFER TO: Rear Lower Arm (204-01B Front Suspension - AWD, Removal and Installation).
     REFER TO: Lower Arm (204-02 Rear Suspension, Removal and Installation).
   • If the measurement is within specification, no further action is required.