Transfer Case

This procedure covers the removal and installation of the transfer case on a 2007 Ram 3500 with 5.9L Cummins diesel engine and 4WD.

Warnings

Tools required

Parts

• Transfer case output shaft seal (rear) × 1 — Use OEM specification
• Transfer case input shaft seal × 1 — Use OEM specification
• Transfer case gasket or RTV sealant × 1 — Use OEM specification
• Skid plate mounting hardware (if corroded) × 1 — Use OEM specification

Fluids

• ATF+4 — 2.5 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery cable
3. Raise vehicle and support securely on jack stands at frame rails
4. Remove front and rear skid plates if equipped
5. Allow transfer case to cool if vehicle was recently driven

Procedure

1. 1

   Drain transfer case fluid
   Position drain pan under transfer case. Remove drain plug from bottom of transfer case and allow fluid to drain completely. Inspect drained fluid for metal particles or unusual debris which may indicate internal damage. Reinstall drain plug finger-tight for now.
2. 2

   Mark and remove front driveshaft
   Using a marker or paint pen, mark the front driveshaft yoke and front axle pinion flange alignment. Remove the bolts (verify count, typically four) securing the front driveshaft to the front differential. Mark the transfer case yoke and front driveshaft alignment at the transfer case end. Remove the four bolts at the transfer case and remove the front driveshaft. Support the driveshaft to prevent damage to CV joint or slip yoke.
3. 3

   Mark and remove rear driveshaft
   Mark the rear driveshaft yoke and rear axle pinion flange alignment. Remove the four bolts/U-bolts securing the rear driveshaft to the rear differential. Mark the transfer case output yoke and rear driveshaft alignment. Remove bolts at transfer case end and remove rear driveshaft. Cap or cover the transfer case output to prevent fluid leakage.
4. 4

   Disconnect shift linkage and wiring
   For electronic shift models, disconnect the transfer case shift motor electrical connector. For manual shift models, disconnect the shift linkage at the transfer case by removing the retaining clip and clevis pin. Label the connector or linkage position if necessary for reinstallation reference.
5. 5

   Disconnect vent hose and speedometer
   Disconnect the transfer case vent hose from the fitting on top of the transfer case. If equipped with mechanical speedometer connection, disconnect the speedometer cable. On vehicles with electronic speed sensors, disconnect the electrical connector.
6. 6

   Support transmission
   Position a jack stand or secondary transmission jack under the transmission tail housing to support the transmission weight once the transfer case is removed. The transmission will lose rear support when the transfer case is detached.
7. 7

   Remove transfer case crossmember
   Support the transfer case with a transmission jack or suitable jack with transfer case adapter. Remove the nuts/bolts securing the transfer case mount to the crossmember. Remove the bolts securing the crossmember to the frame rails. Lower the transfer case slightly and remove the crossmember.
8. 8

   Remove transfer case mounting nuts
   Locate the mounting nuts (verify count against factory service manual, typically six) that secure the transfer case to the transmission adapter housing. These are typically accessed from around the perimeter of the transfer case mounting face. Remove all six nuts while ensuring the transfer case is properly supported on the jack.
9. 9

   Separate and lower transfer case
   Carefully slide the transfer case rearward to disengage the input shaft from the transmission output shaft. You may need to use a pry bar between the transfer case and transmission to help separate them. Once separated, carefully lower the transfer case on the transmission jack and remove from under the vehicle. Keep the unit level to minimize fluid spillage.
10. 10

    Inspect and clean mounting surfaces
    Inspect the transmission output shaft for wear or damage. Check the transfer case input shaft seal and replace if worn. Clean all gasket material from the transmission adapter housing and transfer case mounting surfaces using a wire brush or scraper. Inspect the transfer case mounting studs on the transmission for damage.
11. 11

    Install transfer case
    If replacing seals, install new input shaft seal into transfer case. Apply a thin bead of RTV sealant to the transfer case mounting surface or install new gasket per manufacturer specification. Position the transfer case on the transmission jack and raise into position. Align the transfer case input shaft with the transmission output shaft splines. Carefully slide the transfer case forward onto the transmission, ensuring proper spline engagement. Install all six mounting nuts and tighten in a crossing pattern to ensure even seating.
12. 12

    Install crossmember and mounts
    Raise the transfer case to align with the crossmember mounting position. Install the crossmember to the frame rails and install bolts finger-tight. Install the transfer case mount to crossmember nuts/bolts. Tighten all crossmember and mount hardware to specification, then remove the transmission jack.
13. 13

    Reconnect components
    Reconnect the transfer case vent hose. Reconnect the shift motor electrical connector or manual shift linkage as applicable. Reconnect speedometer cable or speed sensor connector if equipped. Ensure all connections are secure and properly seated.
14. 14

    Install driveshafts
    Install the rear driveshaft, aligning the marks made during removal. Install bolts at both the transfer case and rear differential ends. Install the front driveshaft, aligning all marks made during removal. Tighten all driveshaft bolts securely. Verify all yoke-to-flange alignments match the original marks.
15. 15

    Fill transfer case with fluid
    Remove the fill plug from the side of the transfer case. Using a fluid pump or funnel with hose, add ATF+4 through the fill hole to the correct capacity (verify against factory service manual, typically approximately 2.0 quarts for the NV271/NV273). Fluid should reach the bottom of the fill hole. Install and tighten the fill plug. Tighten the drain plug securely.

Reassembly

1. Reinstall front and rear skid plates if equipped
2. Reconnect negative battery cable
3. Lower vehicle from jack stands

Verification

• Start engine and shift transfer case through all range positions (2H, 4H, 4L, N) to verify proper operation
• Check for fluid leaks around transfer case mounting surface, driveshaft connections, and drain/fill plugs
• Test drive vehicle in 2WD and 4WD modes to verify proper engagement and no unusual noises or vibrations
• Recheck fluid level after test drive and top off if necessary
• Verify no diagnostic trouble codes are present related to transfer case operation

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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