GM Service Manual Online
For 1990-2009 cars only
Table 1: Input Shaft and Planetary Assembly Installation
Table 2: Measuring Clutch Pack Height
Table 3: Clutch Assembly Installation
Table 4: Measuring/Adjusting Clutch Assembly Height
Table 5: Clutch Pressure Plate Installation
Table 6: Rear Output Shaft Assembly
Table 7: Shift Fork Assembly, and Rear Output Shaft Assembly Installation
Table 8: Front Output Shaft Assembly, Drive Chain, Actuator Shaft Gear, and Oil Pump Suction Pipe Installation
Table 9: Transfer Case Rear Case Half Installation
Table 10: Rear Output Shaft Seal and Bushing Installation
Table 11: Access Hole Plugs, Fill and Drain Plug, Vent, 2/4 Wheel Drive Actuator, Actuator Shaft Position Sensor, and Vehicle Speed Sensor Installation
Table 12: Input Shaft Seal and Front Output Shaft Seal Installation

Input Shaft and Planetary Assembly Installation


Object Number: 1849362  Size: MF

Input Shaft and Planetary Assembly Installation

Callout

Component Name

1

Transfer Case Input Shaft Bearing Assembly

2

Transfer Case Input Shaft Inner Retaining Ring

3

Transfer Case High/Low Planetary Carrier Assembly

4

Transfer Case Planetary Carrier Sun Gear Thrust Washer

5

Transfer Case Input Shaft

6

Transfer Case Planetary Carrier Sun Gear Thrust Washer

7

Transfer Case High/Low Locking Plate

8

Transfer Case High/Low Planetary Carrier Retaining Ring

9

Transfer Case Input Shaft/Planetary Assembly

10

Transfer Case Input Shaft Bearing Outer Retaining Ring

Measuring Clutch Pack Height


Object Number: 1849363  Size: MF

Measuring Clutch Pack Height

Callout

Component Name

Preliminary Procedure

    • The DT-48213 gage applies a predetermined amount of pressure to the clutch pack in order to properly measure the clutch pack height. Do not use any other method than what is outlined below.
    • Micrometers or depth gages may also be used in conjunction with the DT-48213 gage to measure the clutch pack height.
    • Two variations are available to measure clutch pack height, outside measurement or inside measurement. Either variation will determine the correct height.

1

Transfer Case Four Wheel Drive Clutch Pressure - Friction - Plates (Qty: 8)

Tip
Install the friction and steel clutch plates into the DT-48213 gage , alternating until 8 friction plates and 7 steel plates are installed.

Special Tools

DT-48213 Clutch Pack Height Gage

For equivalent regional tools, refer to Special Tools.

2

Transfer Case Four Wheel Drive Clutch Pressure - Steel - Plates (Qty: 7)

Procedure 1 - Outside Measurement:

  1. Tighten the DT-48213 gage until the upper portion of the tool contacts the lower portion of the tool. The screw will be flush with the bottom surface of the tool to indicate the tool has fully compressed the clutch plates.
  2. Using an outside caliper, measure the total combined height of the clutch pack and the DT-48213 gage , dimension a. Subtract the thickness of both the upper and lower portion of the DT-48213 gage , 14 mm (0.551 in), and record the results.
  3. Repeat the process in 2 additional locations, 120 degrees from each other.
  4. The average of the 3 measurements is the clutch pack height.

Procedure 2 - Inside Measurement:

  1. Tighten the DT-48213 gage until the upper portion of the tool contacts the lower portion of the tool. The screw will be flush with the bottom surface of the tool to indicate the tool has fully compressed the clutch plates.
  2. Using an inside caliper, measure the height of the clutch pack, dimension b, and record the results.
  3. Repeat the process in 2 additional locations, 120 degrees from each other.
  4. The average of the 3 measurements is the clutch pack height.

Tip
Install the friction and steel clutch plates into the DT-48213 gage , alternating until 8 friction plates and 7 steel plates are installed.

Special Tools

DT-48213 Clutch Pack Height Gage

Clutch Assembly Installation


Object Number: 1849364  Size: MF

Clutch Assembly Installation

Callout

Component Name

1

Transfer Case Rear Output Shaft

2

Transfer Case Control Actuator Lever Thrust Bearing Assembly

3

Transfer Case Control Lever

4

Transfer Case Control Actuator Lever Bearing Assembly

5

Transfer Case Control Actuator Lever Ball (Qty: 3)

6

Transfer Case Control Actuator Lever Assembly

7

Transfer Case Control Actuator Lever Thrust Bearing Assembly

8

Transfer Case Control Actuator Lever Washer

9

Transfer Case Four Wheel Drive Clutch Pressure - Apply - Plate

Tip
Ensure the control actuator lever washer is seated into the apply plate groove.

10

Transfer Case Four Wheel Drive Clutch Pressure Plate Spring (Qty: 4)

11

Transfer Case Four Wheel Drive Clutch Hub

12

Transfer Case Four Wheel Drive Clutch Shim

Tip

    • Use a 3 mm (0.118 in) shim as a base to do the initial measurements with, this shim may be changed in the following steps depending on the results of the stack clearance.
    • Use the original shim if reassembling a transfer case. This shim may be changed in the following steps depending on the results of the stack clearance.

13

Transfer Case Two/Four Wheel Drive Clutch Retaining Ring

Tip
If the clutch shim is not seated against the retaining ring, replace the clutch pressure plate springs.

Measuring/Adjusting Clutch Assembly Height


Object Number: 1849365  Size: MF

Measuring/Adjusting Clutch Assembly Height

Callout

Component Name

1

Clutch Assembly

Procedure:

  1. Using an inside caliper, measure the height of the clutch assembly in the location shown and record the results.
  2. Repeat the process in 2 additional locations, 120 degrees from each other.
  3. The average of the 3 measurements is the clutch assembly height.
  4. A 3.1 mm (0.122 in) clearance +/- 0.1 mm (0.004 in) is necessary between the clutch pack height and the assembly height. It may be necessary to replace the clutch shim with a thicker shim or a thinner shim, to achieve the proper clearance in the clutch.
  5. Subtract the clutch pack height from the clutch assembly height. The difference should be between 3.0 mm (0.118 in) and 3.2 mm (0.126 in) clearance.
  6. Tip

        • A variety of shims are available to properly adjust the clearance height of the clutch assembly.
        • An inside micrometer may also be used to measure the clutch assembly height.

Clutch Pressure Plate Installation


Object Number: 1849366  Size: MF

Clutch Pressure Plate Installation

Callout

Component Name

1

Transfer Case Control Actuator Lever Washer

2

Transfer Case Four Wheel Drive Clutch Pressure - Apply - Plate

3

Transfer Case Four Wheel Drive Clutch Pressure Plate Spring (Qty: 4)

4

Transfer Case Four Wheel Drive Clutch Pressure Plates

5

Transfer Case Four Wheel Drive Clutch Hub

6

Transfer Case Four Wheel Drive Clutch Shim

7

Transfer Case Two/Four Wheel Drive Clutch Retaining Ring

Tip
The Transfer Case High/Low Clutch Reset must be performed after the transfer case is installed in the vehicle.

Rear Output Shaft Assembly


Object Number: 1849367  Size: MF

Rear Output Shaft Assembly

Callout

Component Name

1

Transfer Case Front Output Shaft Drive Sprocket Spacer - Front

2

Transfer Case Four Wheel Drive Clutch Housing

3

Transfer Case Front Output Shaft Drive Sprocket

4

Transfer Case Four Wheel Drive Clutch Housing Retaining Ring

5

Transfer Case Front Output Shaft Drive Sprocket Spacer - Rear

6

Transfer Case Front Output Shaft Drive Sprocket Retaining Ring

7

Transfer Case Oil Pump Assembly

8

Transfer Case Rear Output Shaft Speed Reluctor Wheel

9

Transfer Case Rear Output Shaft Rear Bearing Retaining Ring

10

Transfer Case Rear Output Shaft Rear Bearing Assembly

Tip

    • Use an arbor press or suitable installer to install the bearing to the rear output shaft.
    • Ensure the retaining ring groove in the outer race is positioned toward the rear.

11

Transfer Case Rear Output Shaft Rear Bearing Retaining Ring

Shift Fork Assembly, and Rear Output Shaft Assembly Installation


Object Number: 1849368  Size: MF

Shift Fork Assembly, and Rear Output Shaft Assembly Installation

Callout

Component Name

Preliminary Procedure

Load all 3 components simultaneously.

1

Transfer Case High/Low Shift Fork Assembly

2

Transfer Case High/Low Clutch

3

Transfer Case Rear Output Shaft Assembly

Front Output Shaft Assembly, Drive Chain, Actuator Shaft Gear, and Oil Pump Suction Pipe Installation


Object Number: 1849369  Size: MF

Front Output Shaft Assembly, Drive Chain, Actuator Shaft Gear, and Oil Pump Suction Pipe Installation

Callout

Component Name

1

Transfer Case Front Output Shaft Assembly, Transfer Case Front Output Shaft Drive Chain Assembly

Tip

    • Install the chain with darkened links up.
    • Install the front output shaft assembly into the front case half while engaging the chain with the drive sprocket.

2

Transfer Case Actuator Shaft Gear

3

Transfer Case Oil Pump Suction Pipe Seal

Tip

    • Use a NEW seal.
    • Lubricate the seal to ease installation.
    • Install the seal to the pipe prior to inserting the pipe into the pump.

4

Transfer Case Oil Pump Suction Pipe

Transfer Case Rear Case Half Installation


Object Number: 1849370  Size: MF

Transfer Case Rear Case Half Installation

Callout

Component Name

1

Sealer GM P/N 12345739 (Canadian P/N 10953541), or equivalent

Caution: Apply the proper amount of sealant to the flange when assembling the transfer case. Excessive amounts of sealant can plug the oil pump screen, resulting in internal component failure.

Tip

    • Ensure both sealing surfaces of the front and rear case halves are free of dirt, oil and cleaning solvent.
    • Apply a 2 mm (0.078 in) bead of sealant to the front case half.

2

Transfer Case Rear Case Half

Tip

    • Ensure the transfer case rear output shaft outer retaining ring is in place and aligned prior to mating case halves.
    • Use snap ring pliers to open the transfer case rear output shaft outer retaining ring for the transfer case rear output shaft rear bearing assembly.
    • Insert a rubber coated screwdriver into the speed sensor hole and lift up on the reluctor wheel to engage the retaining ring with the rear bearing assembly.

3

Transfer Case Bracket

4

Transfer Case Bolts (Qty: 17)

Caution: Refer to Fastener Caution in the Preface section.

Tip
Tighten bolts by hand, do not use an air gun.

Tighten
25 N·m (18 lb ft)

Rear Output Shaft Seal and Bushing Installation


Object Number: 1849371  Size: MF

Rear Output Shaft Seal and Bushing Installation

Callout

Component Name

Preliminary Procedures

The following procedure is for the light duty application, for the heavy duty and super heavy duty applications. Refer to Rear Output Shaft Bushing Replacement.

1

Transfer Case Rear Output Shaft Bushing (Light Duty)

Tip

    • If the bushing was removed, a new bushing must be installed.
    • Ensure the bushing is installed squarely into the bushing bore.
    • Follow the steps below for use of the J 45380 remover/installer .
        1. Install the bushing on the finger section of the J 45380 remover/installer .
        2. Install the finger section to the main body of the J 45380 remover/installer .
        3. Position the bushing and tool to the rear case half.
        4. Press the bushing until the tool bottoms on the rear case half.

Special Tools

J 45380 Transfer Case Rear Bushing Remover and Installer

2

Transfer Case Rear Output Shaft Seal (Light Duty)

Tip
Align the notch on the seal between the rear output bearing retaining ring access holes, this will position the weep hole down.

Special Tools

    • DT-48210 Seal Installer
    • J 8092 Driver Handle

3

Transfer Case Rear Output Shaft Seal (Heavy Duty)

Tip
Align the notch on the seal between the rear output bearing retaining ring access holes, this will position the weep hole down.

Special Tools

    • DT-48021 Seal Installer
    • J 8092 Driver Handle

Access Hole Plugs, Fill and Drain Plug, Vent, 2/4 Wheel Drive Actuator, Actuator Shaft Position Sensor, and Vehicle Speed Sensor Installation


Object Number: 1849372  Size: MF

Access Hole Plugs, Fill and Drain Plug, Vent, 2/4 Wheel Drive Actuator, Actuator Shaft Position Sensor, and Vehicle Speed Sensor Installation

Callout

Component Name

1

Transfer Case Actuator Shaft Position Sensor O-Ring Seal

Tip
Lightly lubricate the O-ring with clean DEXRON®VI.

2

Transfer Case Actuator Shaft Position Sensor Assembly

3

Transfer Case Actuator Shaft Position Sensor Bolt/Screw

Tighten
9 N·m (80 lb in)

4

Transfer Case Two/Four Wheel Drive Actuator Assembly

5

Transfer Case Two/Four Wheel Drive Actuator Bolt/Screw

Tighten
18 N·m (13 lb ft)

6

Transfer Case Oil Drain Plug

Caution: Refer to Component Fastener Tightening Caution in the Preface section.

Tip
Apply pipe sealant GM P/N 12346004 (Canadian P/N 10953480) to the oil drain plug before installation.

Tighten
18 N·m (13 lb ft)

7

Transfer Case Oil Fill Plug

Tip
Apply pipe sealant GM P/N 12346004 (Canadian P/N 10953480) to the oil fill plug before installation.

Tighten
18 N·m (13 lb ft)

8

Transfer Case Vent

Tip
Apply retaining compound GM P/N 12377901 (Canadian P/N 10953504) to the vent pipe before installation, if removed during disassembly.

9

Vehicle Speed Sensor O-Ring Seal

Tip
Lightly lubricate the O-ring with clean DEXRON®VI.

10

Vehicle Speed Sensor Assembly

Tighten
17 N·m (13 lb ft)

11

Transfer Case Access Hole Plugs (Qty: 2)

Input Shaft Seal and Front Output Shaft Seal Installation


Object Number: 1849373  Size: MF

Input Shaft Seal and Front Output Shaft Seal Installation

Callout

Component Name

1

Transfer Case Input Shaft Seal

Tip
Ensure the bore of the front case half is free of dirt, oil, and cleaning solvent.

Special Tools

J 42738 Seal Installer

2

Transfer Case Front Output Shaft Seal

Special Tools

    • J 8092 Driver Handle
    • J 43484 Front Output Shaft Seal Installer

3

Transfer Case Assembly

Tip
Remove from J 3289-20 holding fixture and remove the J 45759 assembly fixture from the transfer case.