Transfer Case Motor/Actuator

This procedure covers the removal and replacement of the transfer case shift motor/actuator on a 2007 Ram 3500 with BW 4429 or NV273 transfer case, which controls the electronic shift between 2WD and 4WD modes.

Warnings

Tools required

Parts

• Transfer case shift motor/actuator × 1 — Mopar 68037144AA or equivalent
• Transfer case motor gasket/O-ring × 1 — Usually included with motor

Fluids

• ATF+4 — 0.5 qt

Preparation

1. Park vehicle on level ground and engage parking brake
2. Place transmission in Park (automatic) or gear (manual)
3. Ensure transfer case is in 2WD mode using dash switch
4. Allow vehicle to cool if recently driven
5. Raise front of vehicle and support securely on jack stands
6. Remove any skid plates or protective covers obstructing access to rear of transfer case

Procedure

1. 1

   Locate the transfer case motor
   Position yourself under the vehicle near the transfer case. The shift motor is mounted on the rear driver-side of the transfer case assembly, approximately below the driver's seat area. It is a circular motor assembly with an electrical connector and typically 3-4 mounting bolts.
2. 2

   Disconnect the electrical connector
   Locate the electrical connector on the shift motor. Press the release tab and pull the connector straight away from the motor. If the connector is corroded or stuck, carefully wiggle it while pulling. Do not pull on the wires themselves.
3. 3

   Position drain pan
   Place a drain pan underneath the shift motor location. A small amount of transfer case fluid may drain from the opening when the motor is removed, depending on fluid level and vehicle position. Confirm the correct fluid type (Mopar ATF+4 for NV273) in the owner's manual before servicing.
4. 4

   Remove motor mounting bolts
   Using the correct socket or Torx bit for your fasteners (verify head type on the vehicle), remove the mounting bolts securing the shift motor to the transfer case housing. Note the number of bolts (typically three on the NV273). Keep these bolts as they will be reused. Note the bolt locations if they are different lengths.
5. 5

   Remove the shift motor
   Carefully pull the shift motor straight out from the transfer case housing. It may require slight rotation or wiggling to disengage from the internal shift fork. Once removed, fluid will begin to drain from the opening. Tilt the motor to drain any residual fluid into the pan.
6. 6

   Inspect and clean mounting surface
   Inspect the transfer case opening and mounting surface. Use a wire brush to clean any debris, old gasket material, or corrosion from the mounting flange. Check the internal shift fork (visible through the opening) for damage or wear. Wipe the mounting surface clean with a shop towel.
7. 7

   Prepare new shift motor
   Remove the new shift motor from packaging. Verify it matches the old unit. Install the new gasket or O-ring onto the motor, ensuring it is properly seated in the groove. Apply a light coat of ATF+4 to the O-ring to aid installation and prevent damage.
8. 8

   Install new shift motor
   Align the new shift motor with the opening in the transfer case. The motor must engage with the internal shift fork, so slight rotation may be necessary. Gently push the motor into position until it seats flush against the transfer case housing. Ensure the O-ring does not roll or pinch during installation.
9. 9

   Install mounting bolts
   Install the three mounting bolts and hand-tighten them first to ensure proper alignment. Then tighten the bolts evenly. Tighten firmly but do not over-torque, as the housing is aluminum. Verify the exact torque specification against factory service data (commonly around 21 ft-lbs for these M8 fasteners) before final tightening.
10. 10

    Reconnect electrical connector
    Push the electrical connector onto the shift motor until it clicks into place. Verify the connector is fully seated and the locking tab is engaged. Gently tug on the connector to confirm it is secure.
11. 11

    Check and refill transfer case fluid
    Locate the transfer case fill plug (typically on the side or rear of the case). Remove the fill plug and check fluid level. Add the manufacturer-specified fluid (Mopar ATF+4 for NV273) as necessary until fluid reaches the bottom of the fill hole. Reinstall the fill plug. If significant fluid was lost during motor replacement, top off to the correct level per factory specification.

Reassembly

1. Reinstall any skid plates or protective covers that were removed
2. Lower vehicle from jack stands
3. Start engine and allow to idle

Verification

• With engine running and foot on brake, cycle the transfer case through all positions: 2WD, 4WD High, Neutral, and 4WD Low
• Verify the dash indicator lights properly reflect each selected mode without flashing or error codes
• Listen for normal shift motor operation (a brief whirring sound during mode changes)
• Test drive the vehicle and confirm proper engagement of 4WD when selected
• Check under vehicle for any ATF+4 leaks around the motor mounting area after test drive
• Verify no warning lights or transfer case fault codes are present using the dash display

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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