DEFINITION: A faulty internal transfer case component that causes a growl or grinding noise in the transfer case while the vehicle is turning or in a four wheel drive mode.

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

High/low planetary carrier assembly

1. Inspect the high/low planetary carrier pinion gears for the following conditions:

•	Chipped, bent or deformed teeth

•	Pinion gear bushings worn

•	Pinion gear thrust washers missing

•	Seized or binding pinion gears

•	Refer to Transfer Case Cleaning and Inspection in Transfer Case - Isuzu T150 Unit Repair.

2. Replace the high/low planetary carrier assembly if any of the above conditions exist. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.

Input shaft

1. Inspect the input shaft teeth for excessive wear or damage. Refer to Transfer Case Cleaning and Inspection in Transfer Case - Isuzu T150 Unit Repair.
2. Replace the input shaft if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.

Input shaft thrust bearing

1. Inspect for a faulty input shaft thrust bearing.
2. Inspect the thrust bearing surfaces for galling.
3. Replace the thrust bearing if faulty and the mating component if damaged. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.

Annulus gear

1. Inspect the annulus gear teeth for the following conditions:

•

Damage

•	Chipped teeth

•	Excessive wear

•	Metal embedded in the root of the teeth

•	Refer to Transfer Case Cleaning and Inspection in Transfer Case - Isuzu T150 Unit Repair.

2. Replace the annulus gear if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - Isuzu T150 Unit Repair.