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.

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 high/low 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:
  2. • Worn high/low shift fork pin
    • Worn cam
    • Broken spring
  3. Replace the following components if found faulty:
  4. • The high/low shift fork spring assembly
    • The high/low shift fork pin

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 .

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 .

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 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 .