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

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.

Excessive clearance between the slip yoke and the rear output shaft

1. Inspect for the following conditions:

•	Worn slip yoke splines

•	Worn rear output shaft splines

2. Repair or replace the following components, if faulty:
3. Replace the slip yoke. Refer to Front Propeller Shaft Replacement , One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement in Propeller Shaft.
4. Replace the rear output shaft. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.

Excessive clearance between the slip yoke and the rear bushing

1. Inspect for the following conditions:

•	Worn rear bushing

•	Worn slip yoke bushing journal

2. Replace the slip yoke, if required. Refer to Front Propeller Shaft Replacement , One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement in Propeller Shaft.
3. Replace the rear bushing if worn. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.

Input shaft thrust bearing

1. Inspect for worn or missing input shaft thrust bearings. Refer to Transfer Case Cleaning and Inspection in Transfer Case - Isuzu T150 Unit Repair.
2. Replace the thrust bearings as required. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.

Range sleeve

1. Inspect the range sleeve for the following conditions:

•	Worn engagement teeth

•	Worn internal splines

2. Replace the range sleeve if worn. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.

Rear output shaft bearing outer retaining ring

1. Inspect for the following conditions:

•	Proper installation of the rear output shaft bearing retaining ring

•	Excessive wear or damaged retaining ring groove in the rear case half

2. Repair or replace the following components if found faulty:

•	Properly install a new rear output shaft bearing outer retaining ring.

•	Replace the rear case half if the retaining ring groove is excessively worn. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.