Symptom Chart: NVH

WARNING: This page is about a different car, the 2018 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

Symptom Chart

Condition	Possible Sources	Actions
Axle howling or whine - front or rear axle	Axle lubricant low	CHECK the lubricant level. FILL the axle to specification.
	Axle housing damage	INSPECT the axle housing for damage. INSTALL a new axle housing if necessary. REFER to: Axle Assembly . INSPECT the rear differential subframe bushings. INSTALL a new rear subframe as necessary. REFER to: Rear Subframe - AWD .
	Damaged or worn differential and gear assembly	INSPECT the differential and gear assembly for damage. INSTALL a new axle assembly if necessary. REFER to: Axle Assembly .
Driveline clunk - loud clunk when shifting from REVERSE to DRIVE	Incorrect axle lubricant level	CHECK the lubricant level. FILL the axle to specification.
	Excessive backlash in the axle	CHECK for excessive axle backlash. INSPECT and INSTALL a new axle assembly as necessary. REFER to: Axle Assembly .
Driveline clunk -- occurs as the vehicle starts to move forward following a stop	Loose rear axle mount	CHECK for loose bolts. TIGHTEN to specifications. REFER to: Axle Assembly .
Grinding, popping or chattering - noise from the rear axle when the vehicle is turning	Incorrect or contaminated lubricant	CHECK the vehicle by driving in tight circles (5 clockwise, 5 counter clockwise). DRAIN and REFILL with the specified rear axle lubricant as necessary.
	Damaged or worn differential (differential side gears and pinion gears)	INSPECT and INSTALL a new axle assembly as necessary. REFER to: Axle Assembly .
	Damaged RDU clutch - discs fused from twowheel or extended front to rear differentiation	TEST and INSTALL a new active torque coupling clutch as necessary. REFER to: Active Torque Coupling Clutch .
Grunting -- normally associated with a shudder experienced during acceleration from a complete stop	Loose rear axle mount bolts or suspension fasteners	CHECK for loose bolts. TIGHTEN to specifications. 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 INSTALL a new axle assembly as necessary. REFER to: Axle Assembly .
Chuckle - heard at coast/ deceleration. Also described as knock	Incorrect ring and pinion contact or damaged teeth on the coast side of the ring and pinion	INSPECT and INSTALL a new axle assembly as necessary. REFER to: Axle Assembly .
Knock - noise occurs at various speeds. Not affected by acceleration or deceleration	Gear tooth damage to the driver side of the ring and pinion	INSPECT and INSTALL a new axle assembly as necessary. REFER to: Axle Assembly .
Scraping noise - a continuous low pitched noise starting at low speed	Worn or damaged pinion bearings	INSPECT and INSTALL a new axle assembly as necessary. REFER to: Axle Assembly .
Driveline shudder - occurs during acceleration from a slow speed or stop	Rear drive axle assembly mispositioned	CHECK the axle mounts and the rear suspension for damage or wear. Repair as necessary. REFER to: Axle Assembly .
	Loose rear axle bolts	CHECK the rear axle for loose bolts. TIGHTEN the bolts as necessary. REFER to: Axle Assembly .
	Driveline angles out of specification	CHECK for correct driveline angles.