Symptom Chart - NVH

WARNING: This page is about a different car, the 2012 Ford Pickup. 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 for the next likely system and continue diagnosis.

SYMPTOM CHART - NVH

Condition	Possible Sources	Action
Grinding noise during 4WD engagement, especially at high speeds	Front halfshaft speeds not turning at the same speed Synchronization clutch	GO to Pinpoint Test B .
Vehicle pulsates or shudders in a straight line (straightline driveline wind-up)	Unequal tire inflation pressures Unmatched tire and wheel size Unequal amounts of tire wear Unmatched front and rear axle ratios	GO to Pinpoint Test H .
The front axle makes noise in 2H mode only and generally under heavy throttle	Vacuum leaks Vacuum check valve Vacuum reservoir IWE solenoid IWEs	GO to Pinpoint Test F .
The transfer case makes noise	Tire inflation pressure Tire and wheel size	MAKE SURE that all tires and wheels are the same size and that the inflation pressures are correct.
	Tire tread wear	CHECK tire tread wear to see if there is more than 0.15 mm (0.06 in) difference in tread wear between front and rear. INTERCHANGE one front wheel and one rear wheel. ROAD TEST again.
	Internal components	OPERATE the vehicle in all transmission gears. If there is noise in the transmission in NEUTRAL, or in some gears and not in others, REMOVE and REPAIR the transmission. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 6R80 . If there is noise in all gears, DISASSEMBLE the transfer case. REFER to TRANSFER CASE . CHECK the planetary gears, the bearings, the upper and lower drive sprockets and drive chain for damage. INSTALL new parts as necessary.
	Fluid level	FILL with transfer case fluid. REFER to TRANSFER CASE .
Transfer case whine - noise at all ranges	Incorrect fluid level or fluid quality Worn oil pump Under-inflated or oversized tires	CHECK that the transfer case is filled to the correct level and with the specified fluid. REFER to TRANSFER CASE . DISASSEMBLE the transfer case. CHECK the oil pump for wear or damage. REPAIR as necessary. REFER to TRANSFER CASE . CONFIRM that the tires and wheels are correct for the vehicle. CHECK that the tire inflation pressures are correct.
Transfer case growl/rumble - noise at all ranges	Damaged or worn bearings or planetary gear	DISASSEMBLE the transfer case. CHECK the bearings or planetary gear for wear or damage. REPAIR as necessary. REFER to TRANSFER CASE .
Transfer case scraping/grating - noise at all ranges	Excessively stretched drive chain hitting the case	DISASSEMBLE the transfer case. CHECK the drive chain for wear or damage. REPAIR as necessary. REFER to TRANSFER CASE .
Transfer case howl/hum - noise at all ranges or 4WD only	Worn or damaged sun (input) gear, clutch pack (intermediate) gear or output shaft gear	DISASSEMBLE the transfer case. CHECK the gears for wear or damage. REPAIR as necessary. REFER to TRANSFER CASE .