SAFETY PRECAUTIONS AND TEST PROCEDURES, REAR FINAL DRIVE 0D3 "quattro sport" AND 0BX "quattro sport"

WARNING: This page is about a different car, the 2022 Audi SQ7 and 2022 Audi Q7. However, it is still accessible from the selected car via links, so may be relevant.

Repairs done incorrectly on the rear final drive 0D3 and 0BX "quattro sport" could cause the final drive to malfunction.
Testing, assembling and servicing must be performed by qualified personnel only.

Correct oil level

Make sure the rear final drive is filled to specified oil capacity. Refer to CAPACITIES .
Fix any leaks on the rear final drive, for example, on the sealing surfaces or the seals. The oil can leak out through the holes between the left -arrow 1- or right -arrow 2- chamber and the rear final drive.

Fig 1: Identifying Leaks In Rear Final Drive
Courtesy of AUDI OF AMERICA, LLC

Rear final drive malfunction.
Do not drive the rear final drive if there are leaks or insufficient oil.
Leaks on the rear final drive must be corrected.
Fill the ATF and/or gear oil if the levels are low. Refer to ATF LEVEL, CHECKING and GEAR OIL LEVEL, CHECKING, 0D3 "quattro sport" AND 0BX "quattro sport" .
Only use ATF or gear oil available as a replacement part. Refer to the Parts Information.
If the leaks cannot be repaired, then the rear final drive must be replaced.

Change interval for ATF and gear oil for final drive 0BX "quattro sport"

For the final drive 0BX "quattro sport" for all 90, 000 km (55923.4 miles) a change interval for the gear oil and the ATF is specified. Refer to CAPACITIES, REAR FINAL DRIVE 0BX "quattro sport" .

Rear final drive performance

Transmission control malfunction.
Always maintain all specifications when replacing transmission components. Only by doing so assures the performance and the response characteristics of the rear final drive 0D3 and 0BX "quattro sport".

Replacing transmission components

When replacing the Differential Lock Control Module -J187-, the adaptation values for the transmission aging (for example, clutch wear, oil aging) must be transmitted using the Vehicle Diagnostic Tester, otherwise the performance of the rear final drive may be impaired.
When replacing a chamber or the entire rear final drive, the clutch classification must be entered again in the Differential Lock Control Module -J187- using the Vehicle Diagnostic Tester. If the clutch classification is not performed in the Differential Lock Control Module -J187-, then the rear final drive performance will be impaired. When replacing a chamber, the classification identification on the rear final drive housing must be made unrecognizable. The identification of the new classification is made on the new chamber housing.
Do not place the removed rear final drive on any of the components from the hydraulic control unit (for example, clutch valves). This could damage the components.

Oil Pressure/Temperature Sensor -G437- and/or Oil Pressure/Temperature Sensor 2 -G640-.

The identity of the corresponding sensor in the Differential Lock Control Module -J187- must be re-adapted using the Vehicle Diagnostic Tester after replacing the Oil Pressure/Temperature Sensor -G437- or the Oil Pressure/Temperature Sensor 2 -G640-.
Do not replace both the Oil Pressure/Temperature Sensor -- Oil Pressure/Temperature Sensor -G437- and Oil Pressure/Temperature Sensor 2 Oil Pressure/Temperature Sensor 2 -G640- at the same time because a valid sensor identity is always needed for the rear final drive allocation to the Differential Lock Control Module -J187-. If both sensors are replaced at the same time, the Differential Lock Control Module -J187- will interpret this as the rear final drive is being replaced. By doing this, adaptation values in the control module will be erased and the performance of the rear final drive will be impaired.
If both the Oil Pressure/Temperature Sensor -- Oil Pressure/Temperature Sensor -G437- and Oil Pressure/Temperature Sensor 2 -G640- must be replaced due to mechanical damage, for example, if the connector housing gets damaged, then this must be performed in two steps. After replacing the first sensor, the identity of this sensor must be re-adapted in the Differential Lock Control Module -J187- using the Vehicle Diagnostic Tester. Do the same for the second sensor.
If both the Oil Pressure/Temperature Sensor -- Oil Pressure/Temperature Sensor -G437- and Oil Pressure/Temperature Sensor 2 -G640- must be replaced at the same time due to an electrical fault, then the clutch classification must be re-entered into the Differential Lock Control Module -J187- using the Vehicle Diagnostic Tester. Additionally the ATF must be changed. Refer to ATF, DRAINING AND FILLING .

Torque Displacement, Checking

After the following work, the function 32- Checking the torque displacement must be performed:

Working on the rear final drive wiring
Working on the valves: All-Wheel Drive Clutch Valve -N445- and All-Wheel Drive Clutch Valve 2 -N446-.
Working on the hydraulic control unit