Symptom Chart - NVH: Notes

WARNING: This page is about a different car, the 2013 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: NVH symptoms should be identified using the diagnostic tools that are available. For a list of these tools, an explanation of their uses and a glossary of common terms, refer to NOISE, VIBRATION & HARSHNESS . Since it is possible any one of multiple systems may be the cause of a symptom, it may be necessary to use a process of elimination type of diagnostic approach to pinpoint the responsible system. If this is not the causal system for the symptom, refer back to NOISE, VIBRATION & HARSHNESS for the next likely system and continue diagnosis.

SYMPTOM CHART - NVH

Condition	Possible Sources	Action
Axle howling or whine	Axle lubricant low	CHECK the lubricant level. FILL the axle to specification. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
	Tuned dampers missing or incorrectly installed	REFER to the TSB and follow the procedure outlined.
	Axle housing damage	INSPECT the axle housing for damage. REPAIR or INSTALL a new axle as necessary. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
	Damaged or worn wheel hub bearings	CHECK for abnormal rear wheel bearing play or roughness. INSTALL a new wheel bearing as necessary. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
	Damaged or worn differential ring and pinion	INSPECT and INSTALL a new differential ring and pinion as necessary. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
	Damaged or worn differential side or pinion bearings	INSPECT and INSTALL new differential side or pinion bearings as necessary. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
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 REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
	Excessive backlash in the axle	CHECK the ring gear backlash. REPAIR as necessary. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
	Damaged or worn pinion bearings	REPAIR or INSTALL new pinion bearings as necessary. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
	Damaged or worn U-joints	INSPECT the U-joints for wear or damage. INSTALL new U-joints or driveshaft as necessary. REFER to DRIVESHAFT .
Driveline clunk - occurs as the vehicle starts to move forward following a stop	Worn driveshaft CV joint or U-joints	INSPECT the CV joint and U-joints for wear. INSTALL a new driveshaft or U-joints as necessary. REFER to DRIVESHAFT .
	Loose axle mount	CHECK the axle for loose bolts. TIGHTEN to specification. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
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). FLUSH and REFILL with the specified rear axle lubricant and friction modifier as necessary.
	Damaged or worn differential (differential side gears and pinion gears)	REPAIR or INSTALL new differential side gears or pinion gears as necessary. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
Rumble or boom - noise occurs at coast/deceleration, usually driveshaft speed-related and noticeable over a wide range of speeds	Excessive driveshaft runout and/or driveshaft is out-of-balance	CHECK the driveshaft runout and balance. REFER to DRIVESHAFT RUNOUT AND BALANCING .
	Binding or seized U-joints	ROTATE the driveshaft and CHECK for binding or seized U-joints. INSTALL new U-joints or driveshaft as necessary. REFER to DRIVESHAFT .
Grunting - normally associated with a shudder experienced during acceleration from a complete stop	Binding driveshaft CV joint	INSPECT the driveshaft CV joint for binding. INSTALL a new driveshaft as necessary. REFER to DRIVESHAFT .
	Loose axle mount bolts or suspension fasteners	INSPECT the rear suspension and axle. TIGHTEN the fasteners to specification. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
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 REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
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 REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
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 REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
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 REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
Driveline shudder - occurs during acceleration from a slow speed or stop	Incorrect transmission crossmember orientation	CHECK for correct orientation. REINSTALL if necessary. REFER to UNI-BODY, SUBFRAME AND MOUNTING SYSTEM .
	Center bearing spacer missing or incorrectly installed	CHECK for correct installation of center bearing spacer. REFER to DRIVESHAFT .
	Drive axle assembly mispositioned	CHECK the axle mounts and the rear suspension for damage or wear. REPAIR as necessary. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
	Loose axle bolts	CHECK the axle for loose bolts. TIGHTEN the bolts to specification. REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 8.8-INCH RING GEAR .
	Driveline angles out of specification	CHECK for correct driveline angles. REFER to DRIVELINE ANGLE MEASUREMENT .
	U-joints binding or seized	ROTATE the driveshaft and CHECK for binding or seized U-joints. INSTALL new U-joints or driveshaft as necessary. REFER to DRIVESHAFT .
	Binding or damaged driveshaft CV joint	INSPECT the driveshaft CV joint for binding or damage. INSTALL a new driveshaft as necessary. REPAIR as necessary. REFER to DRIVESHAFT .
Driveline vibration - occurs at cruising speeds	Missing weights or damage to driveshaft	INSPECT the driveshaft. INSTALL a new driveshaft as necessary. REFER to DRIVESHAFT .
	Worn U-joints	CHECK for wear or incorrect seating. INSTALL new U-joints or driveshaft as necessary. REFER to DRIVESHAFT .
	Misalignment of yellow dot on driveshaft-to-yellow dot on pinion flange plus or minus 1 bolt hole	REINSTALL driveshaft with yellow dots aligned plus or minus 1 bolt hole. REFER to DRIVESHAFT .
	Worn or damaged driveshaft center bearing support	CHECK the insulator for damage or wear. ROTATE the driveshaft and CHECK for rough operation. INSTALL a new driveshaft as necessary. REFER to DRIVESHAFT .
	Loose axle pinion flange bolts	INSPECT the axle pinion flange. TIGHTEN the pinion flange bolts to specification. REFER to DRIVESHAFT .
	Excessive axle pinion flange runout	CHECK the pinion flange runout. REPAIR as necessary. REFER to PINION FLANGE RUNOUT CHECK .
	Excessive transmission flange runout	CHECK the transmission flange runout. REPAIR as necessary. REFER to SPECIFICATIONS .
	Binding or damaged driveshaft CV joint	INSPECT the driveshaft CV joint for binding or damage. INSTALL a new driveshaft as necessary. REFER to DRIVESHAFT .
	Excessive driveshaft runout and/or driveshaft out-of-balance	CHECK the driveshaft runout and balance. REFER to DRIVESHAFT RUNOUT AND BALANCING .
	Driveline angles out of specification	CHECK for correct driveline angles. REPAIR as necessary. REFER to DRIVELINE ANGLE MEASUREMENT .
	Transmission mount not centered	NEUTRALIZE the transmission mount. REFER to the Transmission Crossmember procedure in BODY SYSTEM - UNI-BODY, SUBFRAME & MOUNTING SYSTEM .