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

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

High/low planetary carrier assembly

1. Inspect for the following conditions:

•	Excessively worn pinion gears

•	The pinion gears loose in the planetary carrier

2. 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 - Isuzu T150 Unit Repair.

Annulus gear

1. Inspect the annulus gear damper for being faulty. Refer to Transfer Case Cleaning and Inspection in Transfer Case - Isuzu T150 Unit Repair.
2. Replace the annulus gear damper if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.
3. Inspect the tabs for the annulus gear in the front case for excessive wear.
4. Replace the front case half if worn. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.

Range sleeve

1. Inspect the range sleeve engagement teeth for excessive wear.
2. Inspect the range sleeve to rear output shaft splines for excessive wear.
3. Replace the range sleeve if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.

Planetary carrier low gear

1. Inspect the fit of the planetary carrier low gear to the planetary carrier for excessive wear.
2. Inspect the engagement teeth of the planetary carrier low gear to the range sleeve for excessive wear.
3. Replace the planetary carrier assembly if the low gear is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.