GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer case when it is in AWD mode.

Review the Symptoms - Transfer Case and perform the necessary inspections.

Incorrect fluid level or incorrect fluid

  1. Inspect the transfer case for the correct fluid level. Refer 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 Transfer Case Fluid Replacement .

Excessive clearance between the slip yoke and the rear output shaft

  1. Inspect for the following conditions:
  2. • Worn slip yoke splines
    • Worn rear output shaft splines
  3. Repair or replace the following components if faulty:
  4. • Replace the slip yoke, if required. Refer to One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement in Propeller Shaft.
    • Replace the rear output shaft, if required. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 246-NP8 Unit Repair.

Excessive clearance between the slip yoke and the rear bushing

  1. Inspect for the following conditions:
  2. • Worn rear bushing
    • Worn slip yoke bushing journal
  3. Repair or replace the following components if faulty:
  4. • Replace the slip yoke, if required. Refer to One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement in Propeller Shaft.
    • Replace the rear bushing if worn. Refer to Rear Output Shaft Seal Replacement .