Acura RL. Manual - part 366

DRIVE AXLE - NOISE DIAGNOSIS

Unrelated Noises

Some driveline trouble symptoms are also common to the engine, transmission, wheel bearings, tires, and
other parts of the vehicle. Ensure cause of trouble actually is in the drive axle before adjusting, repairing, or
replacing any of its parts.

Non-Drive Axle Noises

A few conditions can sound just like drive axle noise and have to be considered in pre-diagnosis. The 4 most
common noises are exhaust, tires, CV/universal joints and wheel trim rings.

In certain conditions, the pitch of the exhaust gases may e gear whine. At other times, it may be mistaken for
a wheel bearing rumble.

Tires, especially radial and snow, can have a high-pitched tread whine or roar, similar to gear noise. Also,
some non-standard tires with an unusual tread construction may emit a roar or whine.

Defective CV/universal joints may cause clicking noises or excessive driveline play that can be improperly
diagnosed as drive axle problems.

Trim and moldings also can cause a whistling or whining noise. Ensure none of these components are
causing the noise before disassembling the drive axle.

Gear Noise

A "howling" or "whining" noise from the ring and pinion gear can be caused by an improper gear pattern,
gear damage, or improper bearing preload. It can occur at various speeds and driving conditions, or it can be
continuous.

Speed control interlock switch

Lubricate or replace interlock

switch

Clutch Pedal Sticks Down

Binding clutch cable

See CLUTCH article

Springs weak in pressure plate

Replace pressure plate

Binding in clutch linkage

Lubricate and free linkage

Noisy

Dry release bearing

Lubricate or replace release

bearing

Dry or worn pilot bearing

Lubricate or replace bearing

Worn input shaft bearing

Replace bearing

Transmission Click

Weak springs in pressure

Replace pressure plate plate

Release fork loose on ball stud

Replace release fork and/or

ball stud

Oil on clutch disc damper

Replace clutch disc

Broken spring in slave cylinder

Replace slave cylinder

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GENERAL INFORMATION Trouble Shooting - Basic Procedures

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Before disassembling axle to diagnose and correct gear ke sure that tires, exhaust, and vehicle trim have
been checked as possible causes.

Chuckle

This is a particular rattling noise that sounds like a stick against the spokes of a spinning bicycle wheel. It
occurs while decelerating from 40 MPH and usually can be heard until vehicle comes to a complete stop.
The frequency varies with the speed of the vehicle.

A chuckle that occurs on the driving phase is usually caused ive clearance due to differential gear wear, or
by a damaged tooth on the coast side of the pinion or ring gear. Even a very small tooth nick or a ridge on
the edge of a gear tooth is enough the cause the noise.

This condition can be corrected simply by cleaning the gear tooth nick or ridge with a small grinding wheel.
If either gear is damaged or scored badly, the gear set must be replaced. If metal has broken loose, the
carrier and housing must be cleaned to remove particles that could cause damage.

Knock

This is very similar to a chuckle, though it may be louder, and occur on acceleration or deceleration. Knock
can be caused by a gear tooth that is damaged on the drive side of the ring and pinion gears. Ring gear bolts
that are hitting the carrier casting can cause knock. Knock can also be due to excessive end play in the axle
shafts.

Clunk

Clunk is a metallic noise heard when an automatic transmission is engaged in Reverse or Drive, or when
throttle is applied or released. It is caused by backlash somewhere in the driveline, but not necessarily in the
axle. To determine whether driveline clunk is caused by the axle, check the total axle backlash as follows:

1. Raise vehicle on a frame or twinpost hoist so that drive wheels are free. Clamp a bar between axle

companion flange and a part of the frame or body so that flange cannot move.

2. On conventional drive axles, lock the left wheel to keep it from turning. On all models, turn the right

wheel slowly until it is felt to be in Drive condition. Hold a chalk marker on side of tire about 12"
from center of wheel. Turn wheel in the opposite direction until it is again felt to be in Drive
condition.

3. Measure the length of the chalk mark, which is the total axle backlash. If backlash is one inch or less,

drive axle is not the source of clunk noise.

Bearing Whine

Bearing whine is a high-pitched sound similar to a whistle. It is usually caused by malfunctioning pinion
bearings. Pinion bearings operate at drive shaft speed. Roller wheel bearings may whine in a similar manner
if they run completely dry of lubricant. Bearing noise will occur at all driving speeds. This distinguishes it
from gear whine, which usually comes and goes as speed changes.

Bearing Rumble

Bearing rumble sounds like marbles being tumbled. It is usually caused by a malfunctioning wheel bearing.
The lower pitch is because the wheel bearing turns at only about 1/3 of drive shaft speed.

2007 Acura RL

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Chatter On Turns

This is a condition where the entire front or rear of vehicle vibrates when vehicle is moving. The vibration is
plainly felt as well as heard. Extra differential thrust washers installed during axle repair can cause a
condition of partial lock-up that creates this chatter.

Axle Shaft Noise

Axle shaft noise is similar to gear noise and pinion bearing whine. Axle shaft bearing noise will normally
distinguish itself from gear noise by occurring in all driving modes (Drive, cruise, coast and float), and will
persist with transmission in Neutral while vehicle is moving at problem speed.

If vehicle displays this noise condition, remove suspect parts, replace wheel seals and install a new set of
bearings. Re-evaluate vehicle for noise before removing any internal components.

Vibration

Vibration is a high-frequency trembling, shaking or grinding condition (felt or heard) that may be constant
or variable in level and can occur during the total operating speed range of the vehicle.

The types of vibrations that can be felt in the vehicle can d into 3 main groups:



Vibrations of various unbalanced rotating parts of the vehicle.



Resonance vibrations of the body and frame structures caused by rotating of unbalanced parts.



Tip-in moans of resonance vibrations from stressed engine or exhaust system mounts or driveline
flexing modes.

DRIVE AXLE - RWD TROUBLE SHOOTING

DRIVE AXLE (RWD) TROUBLE SHOOTING

NOTE:

This is GENERAL information. This article is not intended to be specific to
any unique situation or individual vehicle configuration. The purpose of this
Trouble Shooting information is to provide a list of common causes to
problem symptoms. For model-specific Trouble Shooting, refer to SUBJECT,
DIAGNOSTIC, or TESTING articles available in the section(s) you are
accessing. For definitions of listed noises or sounds, see DRIVE AXLE -
NOISE DIAGNOSIS under POWERTRAIN.

CONDITION & POSSIBLE CAUSE

CORRECTION

Knocking or Clunking

Differential Side Gear Clearance

Check Clearance

Worn Pinion Shaft

Replace Pinion Shaft

Axle Shaft End Play

Check End Play

Missing Gear Teeth

Check Differential/Replace

Gear

Wrong Axle Backlash

Check Backlash

Misaligned Driveline

Realign Driveline

Clinking During Engagement

2007 Acura RL

GENERAL INFORMATION Trouble Shooting - Basic Procedures

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FWD AXLE SHAFTS & CV JOINTS TROUBLE SHOOTING

BASIC FWD AXLE SHAFTS & CV JOINTS TROUBLE SHOOTING CHART

STEERING & SUSPENSION

MANUAL STEERING GEAR TROUBLE SHOOTING

Side Gear Clearance

Check Clearance

Ring and Pinion Backlash

Check Backlash

Worn/Loose Pinion Shaft

Replace Shaft/Bearing

Bad "U" Joint

Replace "U" Joint

Sticking Slip Yoke

Lube Slip Yoke

Broken Rear Axle Mount

Replace Mount

Loose Drive Shaft Flange

Check Flange

Click/Chatter On Turns

Differential Side Gear Clearance

Check Clearance

Wrong Turn On Plates

(1)

Replace Clutch Plates

Wrong Differential Lubricant

(1)

Change Lubricant

Knock Or Click

Flat Spot on Rear Wheel Bearing

Replace Wheel Bearing

Low Vibration At All Speeds

Faulty Wheel Bearing

Replace Wheel Bearing

Faulty "U" Joint

Replace "U" Joint

Faulty Drive Shaft

Balance Drive Shaft

Faulty Companion Flange

Replace Flange

Faulty Slip Yoke Flange

Replace Flange

(1)

Limited slip differential only.

NOTE:

CONDITION

POSSIBLE CAUSE

Grease Leaks

CV boot torn or cracked

Clicking Noise on Cornering

Damaged outer CV

Clunk Noise on Acceleration

Damaged inner CV

Vibration or Shudder on Acceleration

Sticking, damaged or worn CV Misalignment or

spring height

NOTE:

This is GENERAL information. This article is not intended to be specific to
any unique situation or individual vehicle configuration. The purpose of this

2007 Acura RL

GENERAL INFORMATION Trouble Shooting - Basic Procedures

Friday, June 05, 2009 2:26:48 PM

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