Buick Regal: Symptoms - Rear Differential Carrier
Strategy Based Diagnostics
Review the system operations in order to familiarize yourself with the system
functions. Refer to Rear Drive Axle
Description and Operation, and Power Transfer Unit Case Description and
Operation. All diagnosis on a vehicle should follow a logical process. Strategy
based diagnostics is a uniform approach for repairing all systems. The
diagnostic flow may always be used in order to resolve a system condition. The
diagnostic flow is the place to start when repairs are necessary. For a detailed
explanation, refer to Strategy Based Diagnosis.
Visual/Physical Inspection
- Inspect for aftermarket devices, which could affect the operation of the
vehicle. Checking Aftermarket
Accessories
- Inspect the easily accessible or visible system components for obvious
damage or conditions, which could
cause the symptom.
- Check for the correct lubricant level and the proper viscosity.
- Verify the exact operating conditions under which the concern exists.
Note factors such as vehicle speed, road
conditions, ambient temperature, and other specifics.
- Compare the driving characteristics or sounds, if applicable, to a known
good vehicle and make sure you are
not trying to correct a normal condition.
- Inspect for all-wheel drive activation and operation.
- Factors that may contribute to an inoperative rear differential include:
- Low gear oil levels
- Differential inoperative due to antilock brake system (ABS) function
- Inoperative powertrain control module (PCM) and/or wiring system
- A mini-spare or different size tire installed
- A fluid over-temperature condition
- An inoperative or "stuck" clutch pump check valve
- A defective rear differential assembly
- An inoperative transfer case assembly
Intermittent
Test the vehicle under the same conditions that the customer reported in
order to verify the system is operating
properly.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to
diagnose the symptom:
- Symptoms - Vehicle
- Noisy in Drive
- Noisy When Coasting
- Intermittent Noise
- Constant Noise
- Noisy on Turns
- Rear Differential Carrier Leak Diagnosis
ALL-WHEEL DRIVE (AWD) SYSTEM FUNCTIONAL INSPECTION
Functional Test
Rear axle activation and operation may be checked by positioning the four
wheels off the ground, starting the
vehicle, fully applying the parking brake, and selecting the drive position.
CAUTION: Avoid rear differential damage. Do not exceed 20 percent
accelerator pedal
application or apply throttle for more than 5 seconds while the parking brake is
applied.
Lightly depress the accelerator pedal while watching the rear wheels. They
will rotate slightly as the drive line
winds-up. This indicates the all wheel drive (AWD) is functioning.
NOISY IN DRIVE
NOISY WHEN COASTING
INTERMITTENT NOISE
CONSTANT NOISE
NOISY ON TURNS
REAR DIFFERENTIAL CARRIER LEAK DIAGNOSIS
Definition: A visible indication of an external fluid leak from the
rear diffrerential carrier assembly.
Review the Symptoms - Rear Differential Carrier and perform the necessary
inspections. See below for
suggested diagnostic method (s).
Special Tools
- GE-28431-6 Fluorescent Oil Dye
- GE-42220 Leak Detection Lamp 12V
Equivalent regional tools:Special Tools
Procedure
1. Thorougly clean the suspected leak area using a rag and approved cleaner.
2. Detect the source of the leak:
Fluorescent Dye Method
- Add GE-28431-6 Fluorescent Oil Dye to the rear differential clutch or
differential lubricant to
determine the source of the leak.
NOTE:
Do not drive the vehicle on the freeway as this will splatter oil,
inhibiting leak
diagnosis.
- Operate the vehicle for 15 - 20 minutes under city driving conditions
until normal operating
temperatures are reached.
- Shut OFF the engine.
- Inspect for the presence of dye within the oil leak using the GE-42220
Leak Detection Lamp
12V or equivalent. A presence or non
Powder Method
- Apply an aerosol type leak tracing powder to the suspected leak area.
NOTE:
Do not drive the vehicle on the freeway as this will splatter oil,
inhibiting leak
diagnosis.
- Operate the vehicle for 15 - 20 minutes under city driving conditions
until normal operating
temperatures are reached.
- Shut OFF the engine.
- Trace the leak path through the powder in order to find the source of
the leak.
3. Use the cause and correction below to determine the repair.
READ NEXT:
Removal Procedure
1. Prepare the control module for removal using the SPS programming support
tool.
NOTE: The rear differential clutch control module can now be removed
and replaced.
2. Raise and su
1. Raise and support the vehicle.
2. Clean the area around the rear axle fill plug.
3. Place a drain pan under the vehicle.
4.
Differential Clutch Cover Plug(1) - Remove.
5. Rear Axle Housing Fi
SEE MORE:
Removal Procedure
1.
Front Wheel Bearing and Hub Assembly(1) - Remove.
2.
Steering Linkage Outer Tie Rod(1)@Steering Knuckle - Separate.
3.
Front Lower Control Arm(1)@Steering Knuckle - Separate.
4.
Strut Assembly(1)@Steering Knuckle - Separate.
5.
Remove the steering knuckle (1) from the v
System Component Description
The hydraulic brake system consists of the following:
Hydraulic Brake Master Cylinder Fluid Reservoir
Contains supply of brake fluid for the hydraulic brake system.
Hydraulic Brake Master Cylinder
Converts mechanical input force into hydraulic output pressure.
Hydraulic