DEFINITION: A faulty internal transfer case component that causes a growl or grinding noise from the transfer case.

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

Planetary carrier

1. Inspect the 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 - BW 4473-NP3 Unit Repair.

2. Inspect the planetary carrier for deformation. Refer to Transfer Case Cleaning and Inspection in Transfer Case - BW 4473-NP3 Unit Repair.
3. Replace the planetary carrier assembly if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - BW 4473-NP3 Unit Repair.

Annulus gear

1. Inspect the annulus gear for teeth damage or wear. Refer to Transfer Case Cleaning and Inspection in Transfer Case - BW 4473-NP3 Unit Repair.
2. Replace the annulus gear if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - BW 4473-NP3 Unit Repair.

Sun gear

1. Inspect the sun gear for the following conditions:

•	Gear tooth failure

•	Worn or galled thrust surfaces

•	Refer to Transfer Case Cleaning and Inspection in Transfer Case - BW 4473-NP3 Unit Repair.

2. Replace the sun gear if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - BW 4473-NP3 Unit Repair.

Thrust washers

1. Inspect the thrust washers for seizure to the planetary carrier.
2. Inspect the thrust washers for galling.
3. Replace the thrust washers if faulty and the mating component if damaged. Refer to Transfer Case Disassemble and Transfer Case Assemble in Transfer Case - BW 4473-NP3 Unit Repair.