Section 00-04: Noise, Vibration and Harshness
1996 F-150, F-250, F-350, Bronco and F-Super Duty Workshop Manual
DIAGNOSIS AND TESTING

Pinpoint Tests

These pinpoint tests are designed to take the technician through a step-by-step diagnosis procedure to determine the cause of a condition. It may not always be necessary to follow a chart to its conclusion. Perform only the steps necessary to correct the condition. Then check the operation of the system to be sure the condition has been corrected.

It is sometimes necessary to remove various vehicle components to gain access to the component to be tested. Refer to the applicable section for removal and installation of components. After verifying that the condition has been corrected, make sure all components removed have been reinstalled.

When performing Pinpoint Test A, Shake/Vibration in Drive Under Acceleration/Deceleration diagnosis or Pinpoint TestD, Engine Accessory Vibration diagnosis, observe the following precautions:

 WARNING: IF ONLY ONE DRIVE WHEEL IS ALLOWED TO ROTATE, SPEED MUST BE LIMITED TO 55 KM/H (34 MPH) USING THE SPEEDOMETER READING SINCE ACTUAL WHEEL SPEED WILL BE TWICE THAT INDICATED ON THE SPEEDOMETER. EXCEEDING A SPEED OF 55 KM/H (34 MPH) OR ALLOWING THE DRIVE WHEEL TO HANG UNSUPPORTED COULD RESULT IN TIRE DISINTEGRATION AND/OR DIFFERENTIAL FAILURE, WHICH COULD CAUSE SERIOUS PERSONAL INJURY AND EXTENSIVE VEHICLE DAMAGE.

 

PINPOINT TEST A: SHAKE/VIBRATION IN DRIVE UNDER ACCESSORY/DECELERATION

   

A1 ROAD TEST FOR SHAKE/VIBRATION

Does shake/vibration disappear during neutral coast test?
YesNo
PERFORM Neutral Engine Run-Up Test (NERU) and Drive Engine Run-Up (DERU) Test Under Road Test in the Diagnosis and Testing portion of this section.GO to A2.
 

A2 INSPECT TIRES/WHEELS

Is condition of tires OK?
YesNo
GO to A3.CHECK suspension components for misalignment, abnormal wear or damage that may have contributed to the tire wear. CORRECT suspension concerns and REPLACE damaged tires. PERFORM Road Test.
 

A3 INSPECT WHEEL BEARINGS

Is wheel bearing end play OK?
YesNo
GO to A4.REPLACE wheel bearings as necessary. PERFORM Road Test.
 

A4 TIRE/WHEEL BALANCE

Are tires and wheels balanced?
YesNo
GO to A5.BALANCE tires and wheels as necessary. PERFORM Road Test.
 

A5 MEASURE RUNOUTS

Have all tire/wheel assemblies been measured?
YesNo
GO to A6.COMPLETE Step A5.
 

A6 ANALYSIS OF RUNOUT MEASUREMENT

Do the measurements obtained in A5 fall within specifications listed in Condition 1 in the following chart?


ConditionAssembly Total Radial RunoutWheel Radial RunoutWheel Lateral Runout
1Less Than 1.02mm (0.040 Inch)Less Than 1.14mm (0.045 Inch)Less Than 1.14mm (0.045 Inch)
2Less Than 1.02mm (0.040 Inch)More Than 1.14mm (0.045 Inch)Less Than 1.14mm (0.045 Inch)
3Less Than 1.02mm (0.040 Inch)Less Than 1.14mm (0.045 Inch)More Than 1.14mm (0.045 Inch)
4More Than 1.02mm (0.040 Inch)Less Than 1.14mm (0.045 Inch)Less Than 1.14mm (0.045 Inch)

YesNo
Condition 1 Good Assembly. GO to A14.Condition 2 GO to A7.

Condition 3 GO to A7.

Condition 4 GO to A7.
 

A7 WHEEL HUB BOLT RUNOUT

Is wheel hub bolt runout within the limit?
YesNo
If Condition 2 or 3 from A6, GO to A10. If Condition 4, GO to A11.CHECK for bent or damaged wheel hub bolts. REPLACE as necessary. CHECK wheel hub bolt runout again. If OK, REMEASURE runouts as in A5. If Condition 2 or 3 from A6 persists, GO to A10. If Condition 1, GO to A14. If Condition 4, GO to A11.
 

A8 WHEEL PILOT RADIAL RUNOUT

Is wheel pilot radial runout within the accepted limit?
YesNo
REPAIR or REPLACE as necessary.Go to A9.
 

A9 FLANGE FACE LATERAL RUNOUT

Is flange face lateral runout within the accepted limit?
YesNo
REPAIR or REPLACE as necessary.Go to A10.
 

A10 REPLACING A WHEEL

Is assembly within specification from A6?
YesNo
GO to A13.If Condition 2 or 3, REPLACE wheel and RECHECK. If Condition 4, GO to A11.
 

A11 INDEX TIRE/WHEEL ASSEMBLY

Is total radial runout less than 1.02mm (0.040 inch)?
YesNo
GO to A13.GO to A12.
 

A12 REPLACE A TIRE

Is total radial runout less than 1.02mm (0.040 inch)?
YesNo
GO to A13.INDEX tire/wheel assembly as in A11. If new assembly is now within specifications, GO to A13. If new assembly is still not within specifications, GO to A14.
 

A13 ROAD TEST

Is vehicle operating correctly?
YesNo
Vehicle OK.GO to A14.
 

A14 SUBSTITUTE WHEELS AND TIRES

Is vibration felt?
YesNo
GO to A15.INSTALL original tire/wheel assemblies one by one, ROAD TESTING at each step until the damaged tire(s) is identified. REPLACE tire(s) as necessary and RETEST.
 

A15 VIBRATION DIAGNOSIS OF ENGINE/TRANSMISSION VS. DRIVESHAFT/SUSPENSION COMPONENTS

Was any vibration observed at the wheels?
YesNo
GO to A16.Engine/transmission imbalance. REFER to Group 02, Group 03 and Group 07.
 

A16 ROAD TEST FOR PROPER OPERATION

Is vehicle operating correctly?
YesNo
Vehicle OK.GO to Pinpoint Test E.
 

PINPOINT TEST B: TIP-IN MOAN

   

B1 ENGINE AIR CLEANER

Are components properly installed?
YesNo
GO to B2.CORRECT condition and PERFORM Road Test. If moan persists, GO to B2.
 

B2 ENGINE MOUNTS

Is moan reduced or eliminated?
YesNo
Vehicle OK.GO to B3.
 

B3 EXHAUST SYSTEM

Is moan reduced or eliminated?
YesNo
REPLACE exhaust components as necessary. Vehicle OK.REPEAT Pinpoint Test B. If moan is not eliminated, REFER to Symptom Charts in the Diagnosis and Testing portion of this section for other possible conditions.
 

PINPOINT TEST C: IDLE BOOM/SHAKE/VIBRATION

 

C1 CABLE/HOSES

Are components OK?
YesNo
GO to C2.CORRECT condition and PERFORM Road Test. If boom, shake or vibration persists, GO to C2.
 

C2 ENGINE MOUNTS

Are mounts OK?
YesNo
GO to C3.REPLACE mounts. PERFORM Road Test.
 

C3 EXHAUST SYSTEM

Is system OK?
YesNo
REPLACE exhaust components as necessary. Vehicle OK.GO to Pinpoint Test Step D2.
 

PINPOINT TEST D: ENGINE ACCESSORY VIBRATION

   

D1 ENGINE RUN-UP

Does vibration occur?
YesNo
GO to D2.Vehicle OK.
 

D2 DRIVE BELT AND PULLEYS

Are drive belts or pulleys worn or damaged?
YesNo
REPLACE worn or damaged drive belt or pulleys. CORRECT drive belt tension.GO to D3.
 

D3 MOUNTING HARDWARE

Are mounting and adjusting components secure?
YesNo
GO to D4.ALIGN and TIGHTEN mounting hardware to specifications. CORRECT drive belt tension. START UP engine and RUN UP to problem rpm. If vibration still exists, GO to D4.
 

D4 DRIVE BELT NOISE

Does the noise change?
YesNo
CHECK for misalignment. CHECK tensioner position. CHECK for worn drive belt. SERVICE/REPLACE as required.CHECK accessory bearings. REPLACE as required. GO to D5.
 

D5 DRIVE BELT AND PULLEYS ENGINE IDLING

Was any misalignment or irregular motion detected?
YesNo
REPLACE pulley or drive belt as required.GO to D6.
 

D6 CHECK BELT(S)

Has the vibration been reduced or eliminated?
YesNo
REPLACE the last drive belt removed. If the condition still occurs after replacement, REPAIR/REPLACE accessory.RETURN to Symptom Charts in the Diagnosis and Testing portion of this section for additional possible causes.
 

PINPOINT TEST E: DRIVESHAFT VIBRATION

 

E1 ROAD TEST FOR VIBRATION

Is vibration present?
YesNo
GO to E2.Vehicle OK.
 

E2 ROAD SPEED HOIST TEST

Is vibration present?
YesNo
GO to E3.Vehicle OK.
 

E3 ROAD SPEED HOIST TEST WITH DRIVE WHEELS REMOVED

Is vibration present?
YesNo
GO to E4.GO to A2.
 

E4 DRIVESHAFT INSPECTION

Are driveshaft and universal joints OK?
YesNo
GO to E5.REPAIR as required. PERFORM Road Test. If vibration is still present, GO to E5.
 

E5 CHECKING DRIVESHAFT INDEX MARKS

Are marks more than 22.5 degrees apart?
YesNo
Models with one-piece driveshaft, GO to E6. All others, GO to E7.REFER to driveshaft runout and balancing procedure in Section 05-00.
 

E6 DRIVESHAFT RUNOUT (ONE-PIECE DRIVESHAFT)

Does runout exceed 0.89mm (0.035 inch)?
YesNo
If runout exceeded specs at front and center, REPLACE driveshaft. If runout exceeded specs at rear only, MARK driveshaft at rear runout high point, then GO to E8.REFER to driveshaft runout and balancing procedure in Section 05-00.
 

E7 DRIVESHAFT RUNOUT (TWO-PIECE DRIVESHAFT)

Does runout exceed 0.89mm (0.035 inch)?
YesNo
MARK driveshaft at rear runout high point, then GO to E8.REFER to driveshaft runout and balancing procedure in Section 05-00.
 

E8 INDEXING DRIVESHAFT AT AXLE

Does runout exceed 0.89mm (0.035 inch)?
YesNo
GO to E10.PERFORM Road Test. If vibration is present, GO to E9.
 

E9 INDEXING DRIVESHAFT AT TRANSMISSION

Is vibration still present?
YesNo
REFER to driveshaft runout and balancing procedure in Section 05-00.Vehicle OK.
 

E10 CHECKING REAR AXLE UNIVERSAL JOINT FLANGE FOR EXCESSIVE RUNOUT

Are marks within 25mm (1 inch) of each other?
YesNo
REPLACE driveshaft. PERFORM Road Test. If vibration is present, REFER to driveshaft runout and balancing procedure in Section 05-00.If marks are on opposite sides, REPLACE rear axle universal joint flange. PERFORM Road Test. If vibration is present, REFER to driveshaft runout and balancing procedure in Section 05-00.
 

PINPOINT TEST F: BRAKE VIBRATION/SHUDDER

 

F1 ROAD TEST FOR VIBRATION/SHUDDER

Is vibration/shudder present?
YesNo
INSPECT brake system. REFER to the appropriate section in Group 06. REPAIR as required.REFER to Symptom Charts in the Diagnosis and Testing portion of this section for other conditions.
 

PINPOINT TEST G: AXLE NOISE

 

G1 CHECK DIFFERENTIAL LUBRICANT

Is lubricant level low or not to specification?
YesNo
ADD or REPLACE lubricant. REFER to appropriate section in Group 05.GO to G2.
 

G2 INSPECT AXLE HOUSING

Is axle housing damaged?
YesNo
REPAIR or REPLACE. REFER to appropriate section in Group 05.GO to G3.
 

G3 INSPECT CHATTER ON TURNS

Is chatter noise while turning excessive?
YesNo
PERFORM Road Test. DRIVE vehicle in tight circles, five clockwise and five counterclockwise. If chatter is still evident, ADD specified amount of additive friction modifier meeting Ford specification to the rear axle lube and REPEAT tight circle road test. If still evident, REMOVE differential and SERVICE as necessary. REFER to appropriate section in Group 05.GO to G4.
 

G4 INSPECT AXLE SHAFTS/BEARINGS

Are axle shafts (splines) OK?
YesNo
GO to G5.REPLACE faulty axle shafts. INSPECT all differential gears. REPLACE parts as necessary. PERFORM Road Test.
 

G5 INSPECT RING GEAR BOLTS

Are ring gear bolts OK?
YesNo
GO to G6.TIGHTEN or REPLACE rear gear bolts. INSPECT and REPLACE all damaged parts. REFER to appropriate section in Group 05.PERFORM Road Test.
 

G6 BROKEN OR MUTILATED GEAR TEETH

Are differential gears (ring and pinion) OK?
YesNo
GO to G7.REPLACE faulty gears. REFER to appropriate section in Group 05.
 

G7 CHECK DIFFERENTIAL BEARINGS

Are differential bearings OK?
YesNo
GO to G8.REPLACE faulty bearings. REFER to appropriate section in Group 05. PERFORM Road Test.
 

G8 INSPECT PINION GEAR/BEARINGS

Are pinion bearings OK?
YesNo
Axle OK. REFER to Symptom Charts in the Diagnosis and Testing portion of this section.REPLACE faulty bearings. REFER to appropriate section in Group 05.
 

PINPOINT TEST H: NOISE AND VIBRATION 4-WHEEL DRIVE VEHICLES

 

H1 INSPECT TIRES/WHEELS

Are tires/wheels OK?
YesNo
GO to H2.REPAIR or REPLACE faulty tires. ALIGN if necessary.
 

H2 INSPECT WHEEL BEARINGS

Are wheel bearings OK?
YesNo
GO to H3.REPLACE wheel bearings. CHECK axle or spindle for wear. REFER to appropriate section in Group 05.
 

H3 INSPECT LOCKING HUBS

Are front locking hubs OK?
YesNo
GO to H4.REPAIR or REPLACE as necessary. REFER to Section 05-03C.
 

H4 CHECK TRANSFER CASE FLUID

Is transfer case lubricant OK?
YesNo
GO to H5.REPLACE or FILL fluid in transfer case. REFER to appropriate section in Group 07.
 

H5 INSPECT TRANSFER CASE

Is transfer case OK?
YesNo
REFER to Symptom Charts in the Diagnosis and Testing portion of this section.REPAIR or REPLACE parts as necessary. For service procedures, REFER to appropriate section in Group 07.
 

PINPOINT TEST J: DRIVESHAFT JOINT NOISE AND VIBRATION

 

J1 INSPECT DRIVESHAFT U-JOINTS

Are U-joints OK?
YesNo
GO to J2.REMOVE driveshaft and REPLACE faulty U-joints. REFER to Section05-01.
 

J2 INSPECT DRIVESHAFT/U-JOINTS (DRIVESHAFT REMOVED)

Are U-joints (driveshaft removed) OK?
YesNo
INSPECT driveshaft slip yoke and center bearing support (if equipped). REPLACE if faulty. If OK, REFER to Symptom Charts in this section. REFER to Section 05-01.REPLACE faulty U-joints. REFER to Section 05-01.
 

PINPOINT TEST K: NON-AXLE NOISE

 

K1 INSPECT VEHICLE TRIM

Are vehicle trim components causing noise?
YesNo
REPLACE or REPAIR as necessary. REPEAT road test.GO to K2.
 

K2 BELT SQUEAL OR CHIRP

Is belt or belts OK?
YesNo
GO to K3.REPLACE if necessary. REFER to Section 03-05. For further diagnosis, GO to Pinpoint Test D.
 

K3 INSPECT WHEELS/TIRES

Are wheel and tires OK?
YesNo
GO to K4.REPLACE wheels/tires as necessary. REFER to Section 04-04.
 

K4 INSPECT A/C SYSTEM

Are A/C system components causing noise?
YesNo
GO to K5.REFER to Section 12-00.
 

K5 EXHAUST SYSTEM

Are exhaust clamps and brackets OK?
YesNo
GO to K6.REPAIR or REPLACE if necessary. RESTART engine. If noise still exists, GO to K2.
 

K6 CHECK NON-FACTORY ACCESSORIES

Are accessories the cause of noise?
YesNo
ADJUST, REPAIR or REPLACE accessories and/or fasteners as required.GO to Symptom Charts in the Diagnosis and Testing portion of this section.