Chevrolet Silverado / GMC Sierra. Manual — part 2805

incorrect fluid

to Transfer Case Fluid Replacement.

2. Inspect the transfer case for the correct type of fluid.

3. Flush the transfer case, and fill with the correct fluid, if

required. Refer to Approximate Fluid Capacities.

Excessive clearance
between the slip yoke and
the rear output shaft

1. Inspect for the following conditions:

Worn slip yoke splines

Worn rear output shaft splines

2. Repair or replace the following components if faulty.

Replace the slip yoke, if required. Refer to One-
Piece Propeller Shaft Replacement or Two-
Piece Propeller Shaft Replacement .

Replace the rear output shaft, if required. Refer to
Transfer Case Disassemble andTransfer Case
Assemble .

Excessive clearance
between the slip yoke and
the rear bushing

1. Inspect for the following conditions:

Worn rear bushing

Worn slip yoke bushing journal

2. Repair or replace the following components if faulty.

Replace the slip yoke, if required. Refer to One-
Piece Propeller Shaft Replacement or Two-
Piece Propeller Shaft Replacement .

Replace the rear case half if the rear bushing is
worn. Refer to Transfer Case Disassemble and
Transfer Case Assemble .

Worn or faulty planetary
differential

1. Inspect the planetary differential for the following

conditions:

Loose planetary differential splines to the input
shaft splines

Loose or faulty pinion gears

Refer to Transfer Case Cleaning and
Inspection .

2. Replace the planetary differential assembly if faulty.

Refer to Transfer Case Disassemble and Transfer

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - BW 4485-NR3 - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

TRANSFER CASE LEAK DIAGNOSIS

Case Assemble.

Worn or missing sun gear
thrust washer

1. Inspect to ensure the thrust washer is installed.

2. Inspect the thrust washer and mating surface for excessive

wear.

3. Replace the worn or missing thrust washer. Refer to

Transfer Case Disassemble andTransfer Case
Assemble.

Worn or damaged rear sun
gear

1. Inspect the sun gear external gear teeth for excessive

wear.

2. Inspect the sun gear to rear output shaft for excessive

looseness.

3. Replace the sun gear or rear output shaft if worn. Refer

to Transfer Case Disassemble and Transfer Case
Assemble.

Rear output shaft bearing
outer retaining ring

1. Inspect for the following conditions:

Proper installation of the rear output shaft bearing
retaining ring

Excessive wear or damaged retaining ring groove in
the rear case half

2. Repair or replace the following components if found

faulty:

Properly install a new rear output shaft bearing
outer retaining ring.

Replace the rear case half if the retaining ring
groove is excessively worn.

Refer to Transfer Case Disassemble and
Transfer Case Assemble .

Cause

Correction

DEFINITION: A visible indication of an external fluid leak from the transfer case.
Review the Symptoms - Transfer Case and perform the necessary inspections.
Drain plug or fill plug leak

1. Inspect for the correct sealer and the correct amount of

sealer on the plugs.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - BW 4485-NR3 - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

2. Install the plugs correctly. Refer to Transfer Case Fluid

Replacement.

Rear output shaft seal
leaking

1. Inspect for the following conditions:

Overfilled or improper transfer case fluid

Blocked vent

Seal improperly installed, worn, or damaged

Seal bore damaged or cracked

Rear output shaft bushing for excessive wear

Slip yoke seal surface for wear or pitting

2. Repair or replace the following components if found

faulty:

Adjust or replace the transfer case fluid. Refer to
Transfer Case Fluid Replacement .

Clean, or properly route the vent hose.

Replace the slip yoke if the surface could cause
leakage. Refer to One-Piece Propeller Shaft
Replacement or Two-Piece Propeller Shaft
Replacement .

Replace the rear case half if the bushing is worn.
Refer to Transfer Case Disassemble and
Transfer Case Assemble .

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

Replace the rear output shaft seal. Refer to Rear
Output Shaft Seal Replacement .

Front output shaft seal
leaking

1. Inspect for the following conditions:

Overfilled or improper transfer case fluid

Blocked vent

Seal improperly installed, worn, or damaged

Seal bore damaged or cracked

2. Repair or replace the following components if found

faulty:

Adjust or replace the transfer case fluid. Refer to

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - BW 4485-NR3 - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado