Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Symptom Chart - NVH
2021 Ford Edge SE, 4WDSECTION Symptom Chart - NVH
WARNING: This page is about a different car, the 2018 Ford F-550 Super Duty, 2018 Ford F-450 Super Duty, 2018 Ford F-350 Super Duty, and 2018 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
Diagnostics in this service information assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Diagnostic Methods .
Symptom Chart - NVH
| Condition | Possible Sources | Actions |
|---|---|---|
| Axle howling or whine | Axle lubricant low | CHECK the lubricant level. FILL the axle to specification. REFER to: Differential Fluid Level Check . |
| Axle housing damage | INSPECT the axle housing for damage. REPAIR or INSTALL a new axle as necessary. REFER to: Axle Assembly . | |
| Damaged or worn wheel hub bearings | CHECK for abnormal wheel hub bearing play or roughness. REFER to: Front Wheel Bearing and Wheel Hub . | |
| Damaged or worn differential ring and pinion | INSPECT and INSTALL a new differential ring and pinion as necessary. REFER to: Differential Ring Gear and Pinion . | |
| Damaged or worn differential side or pinion bearings | INSPECT and INSTALL new differential side or pinion bearings as necessary. REFER to: Differential Bearings . | |
| Driveline clunk - loud clunk when shifting from REVERSE to DRIVE | Incorrect axle lubricant level | CHECK the lubricant level. FILL the axle to specification. REFER to: Differential Fluid Level Check (205-03 Front Drive Axle/Differential, General Procedures). |
| Excessive backlash in the axle | CHECK for excessive axle backlash. ADJUST backlash as necessary. REFER to: Differential Ring Gear and Pinion . | |
| Damaged or worn pinion bearings | REPAIR or INSTALL new pinion bearings as necessary. REFER to: Differential Bearings . | |
| Loose or missing fasteners | CHECK all driveline fasteners for proper torque. | |
| Driveline clunk - occurs as the vehicle starts to move forward following a stop | Loose axle mount | CHECK the axle for loose bolts. TIGHTEN to proper torque. REFER to: Axle Assembly . |
| Loose or missing fasteners | CHECK all driveline fasteners for proper torque. | |
| Driveline clunk - occurs during acceleration or from cruise to coast/deceleration | Loose or missing fasteners | CHECK all driveline fasteners for proper torque. |
| High pitched chattering - noise from the axle when the vehicle is turning | Incorrect or contaminated lubricant | CHECK the vehicle by driving in tight circles (5 clockwise, 5 counterclockwise). CLEAN and REFILL the axle to specification. REFER to: Differential Fluid Level Check . |
| Damaged or worn differential (differential side gears and pinion gears) | REPAIR or INSTALL new differential side gears or pinion gears as necessary. REFER to: Differential Carrier . | |
| Grunting - normally associated with a shudder experienced during acceleration from a complete stop | Loose axle mount bolts or suspension fasteners | INSPECT the rear suspension and axle. TIGHTEN the fasteners to specification. REFER to: Axle Assembly . |
| Howl - can occur at various speeds and driving conditions. Affected by acceleration and deceleration | Incorrect ring and pinion contact, incorrect bearing preload or gear damage | INSPECT and REPAIR as necessary. REFER to: Differential Ring Gear and Pinion . |
| Chuckle - heard at coast/deceleration. Also described as a knock | Incorrect ring and pinion contact or damaged teeth on the coast side of the ring and pinion | INSPECT and REPAIR as necessary. Refer to Contact Pattern . |
| Knock - noise occurs at various speeds. Not affected by acceleration or deceleration | Gear tooth damage to the drive side of the ring and pinion | INSTALL a new ring and pinion. REFER to: Differential Ring Gear and Pinion . |
| Scraping noise - a continuous low pitched noise starting at low speeds | Worn or damaged pinion bearings | INSPECT and REPAIR or INSTALL new pinion bearings. REFER to: Differential Ring Gear and Pinion . |
| Driveline shudder - occurs during acceleration from a slow speed or stop | Drive axle assembly mispositioned | CHECK the axle mounts and the rear suspension for damage or wear. REPAIR as necessary. REFER to: Axle Assembly . |
| Loose axle bolts | CHECK the axle for loose bolts. TIGHTEN the bolts to specification. REFER to: Axle Assembly . | |
| Loose or missing fasteners | CHECK all driveline fasteners for proper torque. |
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.