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 shift fork pads for wear. Refer to Transfer Case Cleaning and Inspection in Transfer Case - NVG 236-NP8 Unit Repair.
  2. Replace the fork pads or other damaged components. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 236-NP8 Unit Repair.

Faulty high/low range fork

  1. Inspect the high/low range fork for damage or wear. Refer to Transfer Case Cleaning and Inspection in Transfer Case - NVG 236-NP8 Unit Repair.
  2. Replace the high/low range fork if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 236-NP8 Unit Repair.

Actuator lever worn

  1. Inspect for excessive wear on the actuator lever - for not allowing full shift fork travel. Refer to Transfer Case Cleaning and Inspection in Transfer Case - NVG 236-NP8 Unit Repair.
  2. Replace the faulty actuator lever. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 236-NP8 Unit Repair.

Faulty high speed teeth on range sleeve

  1. Inspect for the following conditions:
  2. • The input gear high speed engagement teeth for wear or damage
    • The engagement teeth on the range sleeve for wear or damage
    • Refer to Transfer Case Cleaning and Inspection in Transfer Case - NVG 236-NP8 Unit Repair.
  3. Replace the range sleeve if the teeth are faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 236-NP8 Unit Repair.
  4. Replace the input gear if the engagement teeth are faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 236-NP8 Unit Repair.

High/low planetary carrier

  1. Inspect for the following conditions of the high/low planetary carrier:
  2. • Low speed engagement teeth worn or damaged
    • Cracked carrier housing
    • Pinion gear bushings worn or out of position
    • Pinion gears broken or damaged teeth
    • Pinion gears seized
    • Refer to Transfer Case Cleaning and Inspection in Transfer Case - NVG 236-NP8 Unit Repair.
  3. Replace the high/low planetary carrier if any of the above conditions are found. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 236-NP8 Unit Repair.

Front input shaft pilot bearing

  1. Inspect the bearing in the input gear and the rear output shaft journal for excessive wear. Refer to Transfer Case Cleaning and Inspection in Transfer Case - NVG 236-NP8 Unit Repair.
  2. Replace the bearing and the rear output shaft if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 236-NP8 Unit Repair.

Input gear

  1. Inspect the input gear for broken or damaged teeth. Refer to Transfer Case Cleaning and Inspection in Transfer Case - NVG 236-NP8 Unit Repair.
  2. Replace the input gear if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 236-NP8 Unit Repair.