2025-12-29

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

Correction code 40300122 0.48 NOTE: Unless otherwise explicitly stated in the procedure, the above correction code and 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. To provide feedback on FRT values, email ServiceManualFeedback@tesla.com. NOTE: See Personal Protection to make sure wearing proper PPE when performing the below procedure. NOTE: See Ergonomic Precautions for safe and healthy working practices.

  • 2025-12-29: Released new procedure.

Remove

  1. Raise and support the vehicle. See Raise Vehicle - 2 Stands.
  2. Remove the rear aero shield. See Aero Shield - Rear (Remove and Replace).
  3. Disconnect the oil pump connector.
  4. Position an oil drain container under the rear of the vehicle.
  5. Remove the fill plug from the rear drive unit.
  6. Release the oil drain plug from the rear drive unit.
  7. Connect 12V power to an oil pump switch box.
  8. Connect the oil pump switch box to the oil pump connector.
  9. Run the oil pump for 1 minute and drain remaining oil from the rear drive unit.
    Informational PurposesAn informational icon, calling your attention
    Note
    Run the pump and allow the full capacity of oil to be drained from the rear drive unit. The pump speed increases when it runs dry. Do not run the pump for more than 10 seconds when it is running dry.
  10. Disconnect the oil pump switch box from the oil pump.

Install

  1. Install the oil drain plug onto the rear drive unit.
    Informational PurposesAn informational icon, calling your attention
    Note
    Make sure that the O-ring is not damaged. Replace the plug as needed.
  2. Set up the fill kit with KAF1.
    Informational PurposesAn informational icon, calling your attention
    Note
    Fill a measuring container to 2.5 ltr. The 4DU rear drive unit will take 2.3 ltr of fluid, but add extra oil to container as it will prevent underfill and additional air being introduced. Only use KAF1 fluid for the 4DU rear drive unit, and do not interchange or mix oil types.
  3. Install the fluid transfer pump.
    Informational PurposesAn informational icon, calling your attention
    Note
    Trim both input and output hoses to 26". Insert output hose into fill hole until fully seated, then pull back 5 mm.
  4. Perform the oil filling process.
    Informational PurposesAn informational icon, calling your attention
    Note
    Place the fluid container in the drain basket, fully submerge input hose, and then prime the pump.
  5. Pump fluid into the rear drive unit.
    Informational PurposesAn informational icon, calling your attention
    Note
    Fill specification for the 4DU is 2.3 ltr. The excess gearbox fluid in the fill container allows the oil pump to dispense the full 2.3L without drawing air. Make sure that there is less than 200 ml left when completed.
  6. Install the oil drain plug onto the rear drive unit.
    Informational PurposesAn informational icon, calling your attention
    Note
    Make sure that the O-ring is not damaged. Replace the plug as needed.
  7. Spray the working area with brake cleaner and wipe residual fluid off with a shop towel.
  8. Remove the oil drain container from underneath the rear drive unit.
  9. Connect the oil pump connector.
  10. Install the rear aero shield. See Aero Shield - Rear (Remove and Replace).
  11. Enable Service Mode Plus. See Service Mode Plus.
  12. Run ODIN routine TEST-SELF_DIR_X_OIL-PUMP-PRESSUREvia Toolbox: (link).
  13. Remove the laptop from the vehicle.
  14. Exit Service Mode Plus. See Service Mode Plus.