DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer case while in the 4HI range only.

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 .

Input gear thrust washers

1. Inspect for worn or missing input gear thrust washers. Refer to Transfer Case Cleaning and Inspection in Transfer Case - NVG 233-NP1 Unit Repair.
2. Replace the thrust washers, as required. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 233-NP1 Unit Repair.

2/4 Wheel drive synchronizer assembly

1. Inspect the synchronizer for the following conditions:

•	The synchronizer hub internal teeth to rear output shaft splines for excessive looseness caused by wear

•	The synchronizer sleeve engagement teeth to the synchronizer gear for wear

•	Refer to Transfer Case Cleaning and Inspection in Transfer Case - NVG 233-NP1 Unit Repair.

2. Replace the synchronizer assembly if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 233-NP1 Unit Repair.

Rear output shaft bearing retaining ring

1. Inspect for the proper installation of the rear output shaft bearing retaining ring.
2. Properly install a new rear output shaft bearing retaining ring. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 233-NP1 Unit Repair.

Worn high speed teeth on the range sleeve

1. Inspect for worn high speed teeth on the range sleeve. Refer to Transfer Case Cleaning and Inspection in Transfer Case - NVG 233-NP1 Unit Repair.
2. Replace the range sleeve if worn. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - NVG 233-NP1 Unit Repair.