GM Service Manual Online
For 1990-2009 cars only

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.

Shift linkage worn

  1. Inspect the shift linkage for correct adjustment or for being worn.
  2. Replace the faulty component. Refer to Transfer Case Control Lever Replacement and Transfer Case Control Rod Replacement .

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 Transfer Case Disassemble and Transfer Case Assemble .

Faulty high speed teeth on the high/low clutch

  1. Inspect for the following conditions:
  2. • The input shaft high speed engagement teeth for wear or damage
    • The engagement teeth on the high/low clutch for wear or damage
  3. Replace the high/low clutch if the teeth are faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
  4. Replace the input shaft if the engagement teeth are faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Faulty control actuator shaft

  1. Inspect the control actuator shaft for wear. Refer to High/Low Shift Components Cleaning and Inspection .
  2. Replace the control actuator shaft if 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:
  2. • 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
  3. 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 .
  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 .