Chevrolet Silverado / GMC Sierra. Service manual — part 2882

TRANSFER CASE JUMPS OUT OF GEAR

Transfer Case Disassemble and Transfer Case
Assemble.

High/low planetary carrier
assembly

1. Inspect the high/low planetary engagement teeth for burrs

or damage. Refer to High/Low Planetary Carrier
Cleaning and Inspection.

2. Replace the high/low planetary carrier assembly if faulty.

Refer to Transfer Case Disassemble and Transfer
Case Assemble.

Cause

Correction

DEFINITION: Loss of the transfer case drive torque during deceleration, acceleration or
under load.
Review the Symptoms - Transfer Case and perform the necessary inspections.

High/low shift fork pads

1. Inspect the high/low shift fork pads for wear. Refer to

High/Low Shift Components Cleaning and
Inspection.

2. Replace the fork pads if worn. Refer to Transfer Case

Disassemble and Transfer Case Assemble.

Faulty high/low shift fork

1. Inspect the high/low shift fork for being damaged. Refer

to High/Low Shift Components Cleaning and
Inspection.

2. Replace the shift fork if faulty. Refer to High/Low Shift

Fork Replacement.

High/low shift fork spring
assembly

1. Inspect the high/low shift fork spring assembly for the

following conditions:

Worn high/low shift fork pin

Worn cam

Broken spring

Refer to High/Low Shift Components Cleaning
and Inspection .

2. Replace the following components if found faulty:

The high/low shift fork spring assembly

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - MP 1625/1626-NQF - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

The high/low shift fork pin

Refer to High/Low Shift Fork Replacement .

Faulty high speed teeth on
the high/low clutch

1. Inspect for the following conditions:

The input shaft high speed engagement teeth for
wear or damage

The engagement teeth on the high/low clutch for
wear or damage

Refer to Front Output Shaft and Input Shaft
Cleaning and Inspection and High/Low Shift
Components Cleaning and Inspection .

2. Replace the high/low clutch if the teeth are faulty. Refer

to Transfer Case Disassemble and Transfer Case
Assemble.

3. Replace the input shaft if the engagement teeth are faulty.

Refer to Transfer Case Disassemble and Transfer
Case Assemble.

High/low planetary carrier
assembly

1. Inspect the high/low planetary carrier for the following

conditions:

Low speed engagement teeth worn or damaged

Cracked carrier housing

Planetary gear needle bearings worn

Planetary gears broken or damaged teeth

Planetary gears seized or binding

Refer to High/Low Planetary Carrier Cleaning
and Inspection .

2. Replace the high/low planetary carrier if any of the

above conditions exist. Refer to Transfer Case
Disassemble and Transfer Case Assemble.

Front output shaft drive
sprocket

1. Inspect the drive sprocket for worn engagement teeth.

Refer to Drive Chain, Drive Sprocket, and Driven
Sprocket Cleaning and Inspection.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - MP 1625/1626-NQF - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

TRANSFER CASE LEAK DIAGNOSIS

2. Replace the drive sprocket if faulty. Refer to Transfer

Case Disassemble and Transfer Case Assemble.

2/4 wheel drive
synchronizer sleeve

1. Inspect the synchronizer sleeve for worn engagement

teeth. Refer to Two/Four Wheel Drive Shift
Components Cleaning and Inspection.

2. Replace the synchronizer sleeve if faulty. Refer to

Transfer Case Disassemble and Transfer Case
Assemble.

Input shaft pilot bearing
assembly

1. Inspect the bearing in the input shaft and the rear output

shaft journal for excessive wear. Refer to Front Output
Shaft and Input Shaft Cleaning and Inspection and

Rear Output Shaft Cleaning and Inspection

.

2. Replace the bearing and the rear output shaft if faulty.

Refer to Input Shaft Pilot Bearing Replacement
(Heavy Duty and Super Heavy Duty) and Transfer
Case Assemble.

Input shaft

1. Inspect the input shaft for broken or damaged teeth.

Refer to Front Output Shaft and Input Shaft
Cleaning and Inspection.

2. Replace the input shaft if faulty. 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. Refer to Sealers, Adhesives, and
Lubricants.

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

Replacement.

Access hole plugs leaking

Replace the access hole plugs or seal with room temperature
vulcanizing (RTV) sealer.

1. Remove the VSS. Refer to Vehicle Speed Sensor

Replacement.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - MP 1625/1626-NQF - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

Vehicle speed sensor (VSS)
leaking

2. Inspect the VSS for the following conditions:

Cross threaded

Cut or damaged VSS O-ring seal

VSS over tightened causing deformation in the VSS

3. Replace the VSS O-ring seal if faulty.

4. Replace the VSS if faulty.

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

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

Replace the rear bushing if worn. Refer to
Transfer Case Rear Extension Bushing
Replacement .

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

1. Inspect for the following conditions:

Overfilled or improper transfer case fluid

Blocked vent

Seal improperly installed, worn or damaged

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - MP 1625/1626-NQF - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado