2026-09-10

Gearbox Fluid - Rear Drive Unit (4DU) (Drainand Refill) (Maintenance)

Correction code 40300122 FRT 0.36 NOTE: Unless otherwise explicitly stated in the procedure, the correction code and its associated FRT reflect all of the work required to perform this procedure, including the linked procedures. Do not stack correction codes unless explicitly told to do so. NOTE: See Flat Rate Times to learn more about FRTs and how they are created. NOTE: See Personal Protection to make sure you are wearing proper PPE when performing the procedure below. NOTE: See Ergonomic Precautions for safe and healthy working practices.

  • 2026-09-10: Released new procedure.
Table 1. Torque Specifications: Gearbox Fluid - Rear Drive Unit (4DU) (Drainand Refill) (Maintenance)
Description Torque Value Recommended Tools Reuse/Replace Notes
The fill plug on the oil plug
15 Nm (11.1 lbs-ft)
  • 8 mm socket
  • 6 in extension
  • Flex head ratchet/flex head torque wrench
  • 8 mm socket
  • 6 in extension
  • Flex head ratchet/flex head torque wrench
 Reuse
The drain plug on the oil plug
15 Nm (11.1 lbs-ft)
  • 8 mm socket
  • 6 in extension
  • Flex head ratchet/flex head torque wrench
  • 8 mm socket
  • 4 in extension
  • Flex head ratchet/flex head torque wrench
 Reuse

Drain

  1. Raise and support the vehicle. See Raise Vehicle - 2 Post Lift.
  2. Remove the rear aero shield panel. See Panel - Aero Shield - Rear (Remove and Replace).
  3. Position an oil drain collector under the rear drive unit oil pump.
  4. Disconnect the oil pump connector.
  5. Remove the fill plug from the oil pump.
    Tip
    Use of the following tool(s) is recommended:
    • 8 mm socket
    • 6 in extension
    • Flex head ratchet/flex head torque wrench
  6. Remove the drain plug from the oil pump.
    Tip
    Use of the following tool(s) is recommended:
    • 8 mm socket
    • 4 in extension
    • Flex head ratchet/flex head torque wrench
  7. Connect the jump pack 12V power supply to the oil pump switchbox harness.
  8. Connect the oil pump switchbox harness to the rear drive unit oil pump connector, and then push in the connector locking tab.
  9. Run the oil pump for 1 minute to drain the remaining gearbox fluid from the rear drive unit.
    CAUTION
    The pump speed increases when it runs dry, do not run the pump for more than 10 seconds when it is dry.
  10. Pull the connector locking tab, and then disconnect the oil pump switchbox harness from the rear drive unit oil pump connector.
  11. Install the drain plug to the oil pump.
    15 Nm (11.1 lbs-ft)
    Note
    Inspect the O-ring for damage, and if the O-ring is damaged, replace the O-ring.
    Tip
    Use of the following tool(s) is recommended:
    • 8 mm socket
    • 6 in extension
    • Flex head ratchet/flex head torque wrench

Refill

  1. Fill a 3000mL measuring container with 2.5L/2500mL of KAF1 gearbox fluid.
    Note
    The rear drive unit requires 2.3L/2300mL of fluid, however the excess fluid will prevent underfill and air entrapment.
  2. If not already the correct length, trim the fluid transfer pump hoses to 26 in (660mm) each.
  3. Install the hoses onto the fluid transfer pump.
  4. Place the measuring container and the fluid transfer pump into the oil drain basket.
  5. Insert the output hose of the fluid transfer pump into the fill hole of the rear drive unit until fully seated, then pull back 5 mm.
  6. Fully submerge the input hose of the fluid transfer pump into the measuring container.
  7. Pump 2.3L/2300mL of KAF1 gearbox fluid into the rear drive unit.
    Note
    Make sure the input hose end remains submerged, so that air is not pumped into the gearbox.
    Note
    When properly filled, there should be 200mL or less of gearbox fluid left in the measuring containter.
  8. Remove the output hose from the rear drive unit.
  9. Install the fill plug to the oil pump.
    15 Nm (11.1 lbs-ft)
    Note
    Inspect the O-ring for damage, and if the O-ring is damaged, replace the O-ring.
    Tip
    Use of the following tool(s) is recommended:
    • 8 mm socket
    • 6 in extension
    • Flex head ratchet/flex head torque wrench
  10. Connect the oil pump connector.
  11. Put on face shielding PPE.
  12. Spray the working area of the rear drive unit with brake cleaner, and then wipe off residual fluid with a clean shop towel.
  13. Remove the oil drain collector out from under the rear drive unit.
  14. Install the rear aero shield panel. See Panel - Aero Shield - Rear (Remove and Replace).
  15. Locally connect a laptop with Toolbox 3 to the vehicle. See Toolbox (Connect and Disconnect).
  16. Run TEST-SELF_DIR_X_OIL-PUMP-PRESSUREvia Toolbox:(link)
  17. Disconnect the laptop.
  18. Exit Service Mode Plus. See Service Mode Plus.
  19. Raise the LH front window and close the LH front door.
  20. Remove the vehicle from the 2 post lift.