Customer's Escape has a growl that gets louder with speed, and it changes when she swerves left or right.

Distinguishing Wheel Bearing vs. Tire Noise

Wheel Bearing Diagnosis:

• Noise characteristics: Deep growl/hum that increases with speed, often changes pitch with load (turning). A bad bearing typically gets louder when turning toward the affected side (weight shifts onto it) and quieter when turning away.
• Physical test: Safely swerve at highway speeds. If noise changes significantly (louder on one side), suspect bearing.
• Jack test: Jack up the suspect wheel, grab at 12 and 6 o'clock, shake hard. Play indicates bearing wear. Spin the wheel—listen for grinding/grittiness.

Tire Diagnosis:

• Noise characteristics: Consistent growl regardless of turning. Often described as "roaring" or "hissing." Cupped/worn tires create steady noise that doesn't change much with swerving.
• Visual inspection: Check tread wear patterns. Cupping (scalloped edges) or feathering (smooth on one side, sharp on other) indicates alignment/balance issues.
• Tire rotation test: Rotate tires front-to-rear. If noise follows the tires, it's tire-related.

Key Differentiator: Bearing noise changes with load/turning; tire noise remains consistent. Since customer's noise changes with swerving, wheel bearing is more likely. Focus on the hub assembly—replace if play or roughness detected.

Diagnostic sequence (15 min max):

1. Tire inspection first — Run hand circumferentially on each tread. Feel for cupping/scalloping (high/low spots) or heel-toe wear. If present, rotate tires front-to-rear. If noise moves with tires → tires. If noise stays at same corner → bearing.

1. Loaded swerve test — At 30–40 mph on smooth pavement, swerve left/right (not lane change, sharp steering input). - Noise louder on right turn → left bearing loaded (weight shifts left). - Noise louder on left turn → right bearing loaded. Tire noise rarely changes pitch this dramatically with load shift.

1. Stethoscope/ChassisEAR — Lift vehicle, spin each wheel by hand. Place probe on knuckle near bearing race (not hub). Compare sides. Bad bearing = roughness, grinding, or metallic growl at specific spot. Tire noise = smooth rumble.

1. Dial indicator — If stethoscope inconclusive, check endplay at wheel flange. Ford spec: ≤0.005″. Excess = bearing.

1. Road force balance — If tires pass #1 but noise persists, road-force balance. >25 lb variation = tire force variation mimicking bearing.

Key differentiator: Bearing noise changes pitch/volume instantly with steering load. Tire noise changes gradually with speed only.

Escape-specific: 2013+ FWD hubs are unitized (bearing + hub + ABS). Press-in requires 20-ton press and new axle nut (torque 185 ft-lb + 180°). AWD rear is bolt-on.

If unsure: Charge 0.5 hr diag. Don't guess — unitized hubs are $180–300 each.