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. Fill the transfer case to the correct fluid level, if required.
3. Inspect the transfer case for the correct type of fluid. Refer to Approximate Fluid Capacities in Transfer Case - NVG 120-NR9 Unit Repair.
4. 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 transfer case 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:

•	Replace the slip yoke, if required. Refer to Rear Propeller Shaft Replacement .

•	Replace the rear output shaft, if required. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 120-NR9 Unit Repair.

Excessive clearance between the slip yoke and the extension bushing

1. Inspect for the following conditions:

•	Worn extension bushing

•	Worn slip yoke bushing journal

2. Repair or replace the following components if faulty:

•	Replace the slip yoke, if required. Refer to Rear Propeller Shaft Replacement .

•	Replace the extension bushing if worn. Refer to Rear Output Shaft Seal Replacement .

Worn or faulty front/rear drive differential carrier assembly

1. Inspect the front/rear drive differential carrier assembly for the following conditions:

•	Loose internal components

•	Resistance or rough operation while rotating internal splines

•	Engagement splines for wear

•	Refer to Front/Rear Drive Differential Carrier Cleaning and Inspection in Transfer Case - NVG 120-NR9 Unit Repair.

2. Replace the front/rear drive differential carrier assembly, if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 120-NR9 Unit Repair.

Worn or missing input shaft thrust bearing washer or wave washer

1. Inspect to ensure the wave washer is installed.
2. Inspect the wave washer and mating surfaces for excessive wear.
3. Replace the worn or missing wave washer. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 120-NR9 Unit Repair.

Worn or damaged input shaft

1. Inspect the input shaft external gear teeth for excessive wear.
2. Replace the input shaft, if worn. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 120-NR9 Unit Repair.