1996 Bronco/F-Series

Section 04-00: Suspension, Service

1996 F-150, F-250, F-350, F-Super Duty and Bronco Workshop Manual

DIAGNOSIS AND TESTING

Pinpoint Tests

PINPOINT TEST A: DRIFT LEFT OR RIGHT

A1 CHECK TIRES

Inspect tires for excessive wear or damage.

Are tires excessively worn or damaged?

Yes	No
REPLACE tires.	GO to A2.

A2 CHECK STEERING LINKAGE

Raise vehicle on hoist. Refer to Section 00-02.
Check steering linkage for indications of excessive wear or damage.

Is there indication of excessive wear or damage?

Yes	No
SERVICE or REPLACE worn or damaged components as necessary.	GO to A3.

A3 CHECK VEHICLE ALIGNMENT

Place vehicle on an alignment rack.
Check vehicle alignment.

Is alignment within specification?

Yes	No
GO to A4.	ADJUST alignment as necessary.

A4 BRAKE DRAG DIAGNOSIS

Does drift or pull occur when brakes are applied?

Yes	No
REFER to Section 06-00 for diagnosis of brakes.	GO to B1.

PINPOINT TEST B: STEERING WHEEL OFF-CENTER

B1 CHECK CLEAR VISION

Place vehicle on alignment rack.

Is clear vision within specifications?

Yes	No
GO to B2.	ADJUST clear vision to specification.

B2 INSPECT STEERING COMPONENTS

Raise vehicle on hoist. Refer to Section 00-02.
Inspect steering components for excessive wear or damage.

Are steering components excessively worn or damaged?

Yes	No
REPLACE or SERVICE worn components. REFER to Section 11-00, Section 04-01A or Section 04-01B.	GO to C1.

PINPOINT TEST C: TRACKS IMPROPERLY

C1 CHECK CASTER

Place vehicle on alignment rack.

Are caster and caster split (LH minus caster) within specification?

Yes	No
GO to C2.	ALIGN vehicle.

C2 CHECK REAR SUSPENSION

Measure vehicle wheel base for LH and RH.
Compare measurements.

Are measurements the same?

Yes	No
GO to D1.	INSPECT rear suspension components for wear or damage. SERVICE or REPLACE worn or damaged components as required. REFER to Section 04-02.

PINPOINT TEST D: ROUGH RIDE

D1 CHECK FRONT SHOCK ABSORBERS

Raise vehicle on hoist. Refer to Section 00-02.
Inspect front shock absorbers for oil leaks or damage.

Are front shock absorbers leaking?

Yes	No
REPLACE front shock absorbers. REFER to Section 04-01A or Section 04-01B.	GO to D2.

D2 CHECK REAR SHOCK ABSORBERS

With vehicle on hoist, inspect rear shock absorbers for oil leak or damage.

Are shock absorbers leaking?

Yes	No
REPLACE shock absorber. REFER to Section 04-02.	Vehicle OK.

PINPOINT TEST E: EXCESSIVE NOISE

E1 INSPECT SUSPENSION

Raise vehicle on hoist. Refer to Section 00-02.
Inspect shock absorber mount bolts.

Are mounting bolts loose or broken?

Yes	No
TIGHTEN/REPLACE shock absorber mount bolts. REFER to Section 04-01A, Section 04-01B or Section 04-02.	GO to E2.

E2 INSPECT SPRINGS

With vehicle on hoist, inspect springs for damage.

Are springs damaged?

Yes	No
REPLACE springs. REFER to Section 04-01A, Section 04-01B or Section 04-02.	GO to E3.

E3 INSPECT FRONT SUSPENSION

Inspect front suspension components for excessive wear or damage.

Are front suspension components worn or damaged?

Yes	No
REPLACE front suspension components. REFER to Section 04-01A or Section 04-01B.	Vehicle OK.

PINPOINT TEST F: IMPROPER TIRE WEAR

F1 INSPECT TIRES

Raise vehicle on hoist. Refer to Section 00-02.
Inspect tires for uneven wear on inner or outer shoulder.

Is there uneven tire wear?

Yes	No
ALIGN vehicle. REPLACE tires if badly worn.	GO to F2.

F2 UNEVEN TIRE WEAR

With vehicle on hoist, inspect tires for sawtooth pattern.

Do tires have sawtooth pattern?

Yes	No
ALIGN vehicle. REPLACE tires if badly worn.	GO to F3.

F3 CHECK FOR CUPPED TIRE

With vehicle on hoist, inspect tires for cupping or dishing.

Are tires cupped or dished?

Yes	No
BALANCE and ROTATE tires. REFER to Section 04-04.	Vehicle OK.

PINPOINT TEST G: VIBRATION

G1 ROAD TEST

Accelerate vehicle to the speed at which the customer indicated the vibration occurred.

Is a vibration present?

Yes	No
GO to G2.	Vehicle OK.

G2 INSPECT WHEEL BEARINGS

Spin front tires by hand to check for wheel bearing roughness. Check bearing end play.

Is end play OK?

Yes	No
GO to G3.	ADJUST or REPLACE and LUBRICATE bearings as necessary. PERFORM road test.

G3 TIRE RUNOUT ON VEHICLE

Measure wheel/tire assembly runouts on vehicle using Rotunda Radial Run-Out Gauge 007-0056A or equivalent. Refer to Section 04-04.

Is measurement in specification?

Yes	No
GO to G8.	GO to G4.

G4 TIRE RUNOUT OFF VEHICLE

Measure tire assembly from any position that exceeds 1.59mm (0.062 inch) radial or lateral. Before removing wheel/tire assembly, mark wheel stud and corresponding bolt hole so assembly can be installed in same position. Remove assembly and mount on wheel balancer. Measure runout as in Step G3. Assembly runout should be less than 1.59mm (0.062 inch) radial and lateral.

Is measurement in specification?

Yes	No
CHECK rotor drum and bolt circle runout. GO to G7.	GO to G5.

G5 MATCH MOUNTING

Mark the high runout location on the tire and also on the wheel. Break the assembly down and rotate the tire 180 degrees (halfway around) on the wheel. Inflate the tire and measure the runouts.

Are tires/wheels balanced?

Yes	No
BALANCE assembly and INSTALL on vehicle. PERFORM road test.	If high spot is not within 101.6mm (4 inches) of first high spot on the tire, GO to G6.

G6 WHEEL RUNOUT

Dismount tire and mount wheel on wheel balancer. Measure runouts on both flanges. Refer to Section 04-04.

Is there proper runout?

Yes	No
LOCATE and MARK low spot on wheel and INSTALL tire, matching high spot on wheel. BALANCE assembly and PERFORM road test.	REPLACE wheel. CHECK runouts on new wheel. If new wheel is within limits, LOCATE and MARK the low spot. INSTALL tire, matching high spot of tire with low spot of wheel. BALANCE assembly and INSTALL on vehicle. PERFORM road test.

G7 INSPECT BRAKES

Inspect the rear brake shoes and linings. Refer to Section 06-00.

Are the rear brake shoes and linings OK?

Yes	No
INSPECT and SERVICE the front disc brakes as necessary. REFER to Section 06-00. PERFORM the road test when complete.	SERVICE the rear brake shoes and linings as necessary. PERFORM a road test when complete.

G8 INSPECT WHEELS

If wheels are equipped with locking wheel hub bolt nuts, check that proper counterbalance wheel weight is installed opposite wheel hub bolt nut.

Is wheel weight correct?

Yes	No
GO to G9.	INSTALL counter. BALANCE wheel weight opposite locking wheel hub bolt nut. PERFORM road test.

G9 FRONT TIRES

Spin front tires with a wheel balance spinner while vehicle is raised on hoist. Feel for vibration in front fender or while seated in vehicle.

Is vibration felt?

Yes	No
BALANCE front wheels. PERFORM road test.	GO to G10.

G10 REAR TIRES

Engage drivetrain while vehicle is raised on hoist. Carefully accelerate the drive wheels while feeling for vibration.

Is vibration felt?

Yes	No
GO to G11.	GO to G13.

G11 DRIVETRAIN

Remove rear wheels, secure brake drums, if so equipped, by installing wheel hub bolt nuts, reversed. Carefully accelerate the drivetrain while feeling for vibration.

Is vibration felt?

Yes	No
GO to G12.	BALANCE rear wheels. PERFORM road test.

G12 WHEEL BALANCE

Balance all wheels not previously balanced. Road test vehicle.

Are wheels balanced?

Yes	No
GO to A1.	GO to G13.

G13 SUBSTITUTE WHEELS AND TIRES

Substitute a known good set of wheels and tires. Road test vehicle.

Is vibration felt?

Yes	No
REFER to Vibration and Roughness.	INSTALL the original tire/wheel assemblies, one by one, road testing at each step, until the defective tire(s) is identified. REPLACE tire(s) as necessary and RETEST.

Ball Joints, Front Suspension Upper Arm and Lower, Twin I-Beam Front Axle Equipped with Joints

Prior to performing any inspection of front suspension lower arm ball joints (3050) or front suspension upper ball joints (3049), adjust the front wheel bearings as described in Section 04-01A or Section 04-01B.

Raise the vehicle and place safety stands under the I-beam axle beneath the spring.

Have an assistant grasp the lower edge of the tire and move the wheel in and out.

While the wheel is being moved, observe the lower spindle arm and the lower part of the axle jaw. A 0.794mm (1/32-inch) or greater movement between the lower portion of the I-beam and the lower spindle arm indicates that the front suspension lower arm ball joint must be replaced.

To check the front suspension upper ball joints, grasp the upper edge of the tire and move the wheel in and out. A 0.794mm (1/32-inch) or greater movement between the upper spindle arm and the upper portion of the I-beam indicates that the front suspension upper ball joint must be replaced.