Symptom Chart

Symptom Chart: NVH 

Condition	Possible Sources	Actions
Axle howling or whine - front or rear axle	Axle lubricant low Axle housing damage Damaged or worn wheel hub bearings Damaged or worn differential ring and pinion Damaged or worn differential side or pinion bearings	CHECK the lubricant level. FILL the axle to specification. INSPECT the axle housing for damage. INSTALL a new RDU as necessary. REFER to Rear Drive Axle Differential CHECK for abnormal wheel hub bearing play or roughness. REFER to Front Suspension or REFER to Rear Suspension . INSPECT and INSTALL a new RDU as necessary. REFER to Rear Drive Axle Differential INSPECT and INSTALL a new RDU as necessary. REFER to Rear Drive Axle Differential
Driveline clunk - loud clunk when shifting from REVERSE to DRIVE	Incorrect axle lubricant level Excessive backlash in the axle Damaged or worn pinion bearings Damaged or worn U-joints Loose hub nut	CHECK the lubricant level. FILL the axle to specification. CHECK the axle backlash. INSPECT and INSTALL a new RDU as necessary. REFER to Rear Drive Axle Differential INSTALL a new RDU as necessary. REFER to Rear Drive Axle Differential INSPECT the U-joints for wear or damage. INSTALL new driveshaft as necessary. REFER to Driveshaft CHECK the torque on the hub nut. REPLACE the hub nut if the torque is not at specification. For front hub nuts REFER to Front Drive Halfshafts , REFER to Front Drive Halfshafts (RH), REFER to Front Drive Halfshafts (LH) or for rear hub nuts REFER to Rear Drive Halfshafts
Driveline clunk - occurs as the vehicle starts to move forward following a stop	Worn driveshaft CV joint or U-joint with excessive play Loose rear axle mount Loose hub nut	INSPECT the CV joint and U-joint for a worn condition. INSTALL a new driveshaft as necessary. REFER to Driveshaft CHECK the axle for loose bolts. TIGHTEN to specification. REFER to Rear Drive Axle Differential . CHECK the torque on the hub nut. REPLACE the hub nut if the torque is not at specification. For front hub nuts REFER to Front Drive Halfshafts (RH) (AWD), REFER to Front Drive Halfshafts (RH) (FWD), REFER to Front Drive Halfshafts (LH) or for rear hub nuts REFER to Rear Drive Halfshafts
Driveline clunk FWD vehicles - occurs during acceleration or from cruise to coast/deceleration	Damaged or worn inner CV joint Loose hub nut	INSPECT the inner CV joint and boot. INSTALL a new CV joint as necessary. REFER to Front Drive Halfshafts (RH) (AWD), REFER to Front Drive Halfshafts (RH) (FWD), REFER to Front Drive Halfshafts (LH) CHECK the torque on the hub nut. REPLACE the hub nut if the torque is not at specification. For front hub nuts REFER to Front Drive Halfshafts (RH) (AWD), REFER to Front Drive Halfshafts (RH) (FWD), REFER to Front Drive Halfshafts (LH) or for rear hub nuts REFER to Rear Drive Halfshafts
Clicking, popping or grinding - occurs while the vehicle is turning	Inadequate or contaminated lubrication in the CV joints Another component contacting the halfshaft	CHECK the CV boots and joints for wear or damage. INSTALL new components as necessary. REFER to Front Drive Halfshafts (RH) (AWD), REFER to Front Drive Halfshafts (RH) (FWD), REFER to Front Drive Halfshafts (LH). CHECK the halfshafts and the area around the halfshafts. REPAIR as necessary. CHECK the halfshafts and the area around the halfshafts. Install an outer halfshaft thrust washer between the outer CV joint housing and the hub interface as necessary.
Ting, pop, or click noise from the front wheel area when accelerating from a stop or when shifting between drive/reverse and/or reverse/drive.	Halfshaft to hub interface.	INSTALL or REPLACE thrust washer between the halfshaft and hub. The nylon surface should face outward toward the hub/splines. REFER to Front Drive Halfshafts .
High pitched chattering - noise from the rear axle when the vehicle is turning	Incorrect or contaminated lubricant Damaged or worn differential (differential side gears and pinion gears)	CHECK the vehicle by driving in tight circles (5 clockwise, 5 counterclockwise). FLUSH and REFILL with the specified rear axle lubricant. INSTALL a new RDU as necessary. REFER to Rear Drive Axle Differential .
Buzz - buzzing noise is the same at cruise or coast/deceleration	Incorrect driveline angles	CHECK for correct driveline angles. REPAIR as necessary. REFER to Driveline Angle Measurement .
Rumble or boom - noise occurs at coast/deceleration, usually driveshaft speed related and noticeable over a wide range of speeds	Driveshaft is out of balance Universal-Joint (U-Joint) are binding or seized	CHECK the driveshaft for damage, missing balance weights or undercoating. REFER to Driveshaft Runout and Balancing . ROTATE the driveshaft and CHECK for rough operation or seized U-joints. INSTALL new driveshaft as necessary. REFER to Driveshaft
Grunting - normally associated with a shudder experienced during acceleration from a complete stop	Driveshaft CV joint binding Loose rear axle mount bolts or suspension fasteners	INSTALL a new driveshaft as necessary. REFER to Driveshaft INSPECT the rear suspension and axle. TIGHTEN the fasteners to specification. REFER to Rear Drive Axle Differential .
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	INSTALL a new RDU as necessary. REFER to Rear Drive Axle Differential
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	INSTALL a new RDU as necessary. REFER to Rear Drive Axle Differential
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 RDU as necessary. REFER to Rear Drive Axle Differential
Scraping noise - a continuous low pitched noise starting at low speeds	Worn or damaged pinion bearings	INSTALL a new RDU as necessary. REFER to Rear Drive Axle Differential
Driveline shudder - occurs during acceleration from a slow speed or stop	Rear drive axle assembly mispositioned Loose rear axle bolts Driveline angles out of specification U-joint binding or seized Binding or damaged driveshaft CV joint	CHECK the axle mounts and the rear suspension for damage or wear. REPAIR as necessary. REFER to Rear Drive Axle Differential . CHECK the rear axle for loose bolts. TIGHTEN the bolts to specification. REFER to Rear Drive Axle Differential . CHECK for correct driveline angles. REFER to Driveline Angle Measurement . ROTATE the driveshaft and CHECK for rough operation or seized U-joints. INSTALL new driveshaft as necessary. REFER to Driveshaft INSPECT the driveshaft CV joint and coupling shaft for wear or damage. INSTALL a new driveshaft as necessary. REPAIR as necessary. REFER to Driveshaft
Driveline vibration - occurs at cruising speeds	Worn U-joint Worn or damaged driveshaft center bearing support Loose axle pinion flange bolts Excessive axle pinion flange runout Driveshaft is out of balance Binding or damaged driveshaft CV joint Excessive driveshaft runout Driveline angles out of specification Incorrectly seated CV joint in the wheel hub	CHECK for wear or incorrect seating. INSTALL new driveshaft as necessary. REFER to Driveshaft CHECK the insulator for damage or wear. ROTATE the driveshaft and CHECK for rough operation. INSTALL a new driveshaft as necessary. REFER to Driveshaft INSPECT the axle pinion flange. TIGHTEN the pinion flange bolts to specification. REFER to Driveshaft CARRY OUT a runout check. REPAIR as necessary. REFER to Rear Drive Axle Differential . CHECK the driveshaft for damage, missing balance weights or undercoating. CHECK the driveshaft balance. CARRY OUT a driveline vibration test. REFER to Driveshaft Runout and Balancing . INSPECT the driveshaft CV joint for wear or damage. INSTALL a new driveshaft as necessary. REFER to Driveshaft CARRY OUT a runout check. REFER to Driveshaft Runout and Balancing . CHECK the outer CV joint for correct seating into the hub. REPAIR as necessary. REFER to Front Drive Halfshafts (RH) (AWD), REFER to Front Drive Halfshafts (RH) (FWD), REFER to Front Drive Halfshafts (LH) for the front CV joints or REFER to Rear Drive Halfshafts for the rear CV joints.

Analysis of Leakage 

Clean up the leaking area enough to identify the exact source.

A plugged RDU housing vent can cause excessive pinion seal lip wear due to internal pressure buildup.

Verify the RDU lubricant level is even with the bottom of the fill hole.

Axle Vent 

A plugged vent will cause excessive seal lip wear due to internal pressure buildup. If a leak occurs, check the vent. If the vent cannot be cleared, install a new vent.

Drive Pinion Seal 

Leaks at the drive pinion seal originate from the following causes:

• Damaged seal
• Worn seal journal surface

Any damage to the seal bore (dings, dents, gouges or other imperfections) distorts the seal casing and allows leakage past the outer edge of the drive pinion seal.

The drive pinion seal can be torn, cut or gouged if it is not installed correctly. The spring that holds the drive pinion seal against the pinion flange may be knocked out and allow fluid to pass the lip.

Metal chips trapped at the sealing lip can cause oil leaks. These can cause a wear groove on the drive pinion flange and result in pinion seal wear.

When a seal leak occurs, Install a new drive pinion seal and check the vent to make sure it is clean and free of foreign material.

A new drive pinion flange must be installed if any of these conditions exist.

Drive Pinion Nut 

Halfshaft pilot bearing housing seals are susceptible to the same types of damage as drive pinion seals if incorrectly installed. The seal bore must be clean and the lip handled carefully to avoid cutting or tearing it. The seal journal surface must be free of nicks, gouges and rough surface texture. REFER to Rear Drive Axle Differential