Chevrolet Silverado / GMC Sierra. Manual — part 2840

Clean or properly route the vent hose.

Replace the front output shaft seal. Refer to Front
Output Shaft Seal Replacement .

Replace the front case half if the seal bore is
damaged. Refer to Transfer Case Disassemble
and Transfer Case Assemble .

Replace the cup plug in the front output shaft if
leaking. Refer to Transfer Case Disassemble and
Transfer Case Assemble .

Shift lever seal leaking

Replace the shift lever seal. Refer to Transfer Case
Disassemble and Transfer Case Assemble.

Leaking at the vent pipe

Transfer case overfilled

Inspect for the correct transfer case fluid level. Refer to
Transfer Case Fluid Replacement.

Inspect for a damaged or missing vent pipe.

Replace a damaged or missing vent pipe and seal the vent
pipe with the correct sealer. Refer to Transfer Case
Assemble.

Transfer case to adapter
leak

1. Inspect for the following conditions:

Loose mounting fasteners

Gasket faulty

The transfer case input shaft seal leaking

The pilot bearing in the input shaft leaking

2. Repair or replace the following components if found

faulty:

Repair or replace the loose fasteners. Refer to
Transfer Case Adapter Replacement .

Replace the transfer case adapter gasket. Refer to
Transfer Case Adapter Replacement .

Replace the transfer case input shaft seal. Refer to
Input Shaft Seal Replacement .

Inspect for the following conditions:

Seal improperly installed, worn, or damaged

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - MP 1222/1225/1226-NQG - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

REPAIR INSTRUCTIONS - ON VEHICLE

TRANSFER CASE CONTROL LEVER REPLACEMENT

Fig. 4: Transfer Case Control Lever
Courtesy of GENERAL MOTORS CORP.

Seal bore damaged or cracked

Input shaft seal surface worn, grooved, or
damaged

Replace the pilot bearing in the input shaft if
leaking. Refer to Transfer Case Disassemble and
Transfer Case Assemble .

Case leaking

1. Inspect for the following conditions:

A cracked case

Case porosity

2. Replace the faulty case half. Refer to Transfer Case

Disassemble and Transfer Case Assemble.

Front case half to rear case
half seam leak

Disassemble and seal the case halves. Refer to Transfer Case
Disassemble and Transfer Case Assemble.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - MP 1222/1225/1226-NQG - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

TRANSFER CASE CONTROL ROD REPLACEMENT

Removal Procedure

Callout

Component Name

Preliminary Procedures

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

2. Remove the transfer case shield, if equipped. Refer to Transfer Case Shield

Replacement .

3. Remove the front propeller shaft. Refer to Front Propeller Shaft Replacement .

4. Remove the control rod. Refer to Transfer Case Control Rod Replacement.

1

Transfer Case Control Lever Knob

Procedure

1. Using an adjustable wrench, adjust the wrench to fit the control lever rod

just below the knob.

2. With the adjustable wrench touching the control lever knob, gently tap on

the adjustable wrench in an upward motion until the knob is separated
from the control lever rod.

2

Transfer Case Control Lever Bezel Cover

3

Transfer Case Control Lever Bezel Screw (Qty: 3)

Tighten: 12 N.m (106 lb in)

NOTE:

Refer to Fastener Notice .

4

Transfer Case Control Lever Bezel

5

Transfer Case Control Lever Bolt (Qty: 4)
Tip: Tighten bolts in specified sequence.

Tighten: 25 N.m (18 lb ft)

6

Transfer Case Control Lever

IMPORTANT: Before beginning the following service procedure, place the

transmission into the PARK position. Then place the transfer
case in the 2 HI position.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - MP 1222/1225/1226-NQG - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado