Pinpoint Tests L: Front End Noise - Driving Straight On Smooth Roads

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L1: CHECK TIRE CONDITION

Check tires for wear, damage, uneven tread or miss-matched tires (miss-matched tires are especially important on AWD and 4x4 systems).
Verify all 4 tires are matching size and brand.
Are the tires free from wear, damage, uneven tread or miss-matching issues?

Yes	No
Go to L2.	INSTALL new tires as necessary. REFER to the Wheels and Tires article.

L2: CHECK FOR NOISE CHANGE DURING BUMPS AND VARYING SPEEDS

Test drive the vehicle and confirm the noise.
- Make sure to drive over bumps and vary the vehicle speed during the test.
Was the noise affected by bumps?

Yes	No
GO to PINPOINT TEST AC.	If the noise was affected by vehicle speed, Go to L3.

L3: VISUAL INSPECTION FOR NOISE SOURCE

The following components can cause noise issues while rotating. Inspect the following components for looseness, wear and damage:
- Wheel hubs and bearings
- Axle shafts or halfshafts (includes center support bearing)
- Drive shafts and pinion bearings
- Left and right inner CV joints
- PTO output shaft (FWD only)
- Transfer case assembly (if equipped)
- Integrated wheel ends and associated vacuum system (4x4 only)
- Drive shaft center support bearing (RWD only)
The following components can cause noise issues while being disturbed by the wind. Inspect the following undercarriage components for looseness, wear, witness marks or damage:
- Heat shields
- Wiring harnesses
- Tubes and hoses
- Wheel well linings and splash shields
- Air dams
- Radiator ducts or shields
- Other components not retained
Are all of the listed components OK?

Yes	No
Go to L4.	REPAIR or INSTALL new components as necessary.

L4: VEHICLE ON-HOIST INSPECTION

With the transmission in NEUTRAL, position the vehicle on a hoist. Refer to the Jacking And Lifting. article.
Raise the vehicle until the wheels can spin freely.
Start the vehicle.
- Make sure the engine ready indicator is illuminated.
Disable the AdvanceTrac or traction control system (if equipped).
Bring the vehicle up to speed where the reported noise can be heard.
Listen for the noise.
Was the noise able to be replicated with the vehicle on the hoist?

Yes	No
Using a listening device, such as Chassis Ears, LOCATE the causal component. REPAIR or INSTALL new as necessary.	Go to L5.

L5: ROAD TEST NOISE VERIFICATION

Using a listening device, such as Chassis Ears:
- Attach probe 1 to the back side of the left front wheel knuckle or spindle.
- Attach probe 2 to the back side of the right front wheel knuckle or spindle.
Using an assistant to test drive the vehicle, attempt to duplicate the noise while listening to the device.
Is the reported noise also heard through probe 1 or 2?

Yes	No
The noise may be caused by the wheel bearing or related components. INSPECT and REPAIR or INSTALL new as necessary (brake components, integrated wheel ends, etc.).	REFER to the list of possible sources in step L3 for further evaluation of noise sources, or REFER to the Noise, Vibration And Harshness - F450 - F600 Super Duty. article to continue NVH diagnostics.