Symptom Chart: NVH

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

Diagnostics in this article assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Diagnostic Methods .

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 and INSTALL a new axle assembly as necessary. REFER to: Axle Assembly . INSPECT and INSTALL new rear differential subframe bushings as necessary. REFER to: Rear Differential Subframe Bushings .
	Damaged, worn or incorrect ring and pinion gear contact	INSPECT and INSTALL a new axle assembly as 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. REFER to: Differential Fluid Level Check .
	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	Damaged RDU clutch - discs fused from two-wheel or extended front to rear differentiation	INSPECT and INSTALL a new axle assembly as necessary. REFER to: Axle Assembly .
	Damaged or worn differential (differential side gears and pinion gears)	INSPECT and INSTALL a new axle assembly as necessary. REFER to: Axle Assembly .
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. REFER to: Driveshaft Angle Measurement .