Lincoln Nautilus: Suspension System - General Information / Suspension System. Diagnosis and Testing

Preliminary Inspection

1. Road test the vehicle.
   
   • If any suspension alignment or ride height concerns are present, REFER to Symptom Chart: Suspension System.
     
   • Verify the customer concern by carrying out a road test on a smooth road. If any vibrations are present, REFER to Symptom Chart: NVH .
     

1. 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.
     

1. 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.
     
   • Wheel bearing and wheel hub(s).
     

1. 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 manual do not apply to vehicles equipped with aftermarket equipment.
     

Symptom Chart: Suspension System

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).

• If an obvious cause for an observed or reported condition is found, correct the cause (if possible) before proceeding to the next step.
• If the fault is not visually evident, REFER to Symptom Chart or REFER to Symptom Chart: NVH.

Symptom Chart: NVH

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).

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, Glossary of Terms
REFER to: Noise, Vibration and Harshness (NVH) (100-04 Noise, Vibration and Harshness, Diagnosis and Testing).
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) (100-04 Noise, Vibration and Harshness, Diagnosis and Testing).
for the next likely system and continue diagnosis.

Additional diagnostics may be necessary to further isolate the concern. An electronic listening tool such as Chassis Ear® may be used. Follow the tool manufacturer’s instructions and the Possible Sources found in the following NVH chart to determine the connection points.

Pinpoint Tests

Diagnostic Overview

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).

Component Tests

Ball Joint Inspection

1. Prior to inspecting the ball joints for wear, inspect the wheel bearings. Install a new wheel bearing as necessary.
   REFER to: Front Wheel Bearing and Wheel Hub (204-01 Front Suspension, Removal and Installation).

1. NOTE: In order to obtain accurate measurements, the suspension must be in full rebound with the weight of the vehicle supported by the frame.

   Raise and support the vehicle by the frame to allow the wheels to hang in the rebound position.
   REFER to: Jacking and Lifting - Overview (100-02 Jacking and Lifting, Description and Operation).

1. Inspect the ball joint and ball joint boot for damage.
   
   • If the ball joint or ball joint boot is damaged, install a new lower control arm as necessary.
     REFER to: Lower Arm (204-01 Front Suspension, Removal and Installation).

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

   Inspect the ball joint for relative movement by alternately pulling downward and pushing upward on the lower control arm by hand. Note any relative vertical movement between the wheel knuckle and lower control arm at the lower ball joint.
   
   • If relative movement is not felt or seen, the ball joint is OK. Do not install a new lower control arm.
     
   • If relative movement is found, continue with Step 5.
     

1. NOTE: In order to obtain an accurate measurement, the dial indicator should be aligned as close as possible with the vertical axis (center line) of the ball joint.

   To measure ball joint deflection, attach a suitable dial indicator with a flexible arm between the lower control arm and the wheel knuckle or ball joint stud.
   

1. Measure the ball joint deflection while an assistant pushes up and pulls down on the lower control arm, by hand.
   
   • If the deflection exceeds the specification, a new lower control arm must be installed.
     REFER to: Lower Arm (204-01 Front Suspension, Removal and Installation).
   • If the deflection meets the specification, no further action is required.