Transfer Case Clunk in 4HI Lock

Cause	Correction
DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer case while in the 4HI Lock range only. Review the Symptoms - Transfer Case and perform the necessary inspections.
Incorrect fluid level or incorrect fluid	Inspect the transfer case for the correct fluid level. Refer to Transfer Case Fluid Replacement . Inspect the transfer case for the correct type of fluid. Flush the transfer case and fill with the correct fluid, if required. Refer to Approximate Fluid Capacities .
Worn high speed teeth on the range sleeve	Inspect for worn high speed teeth on the range sleeve. Refer to Transfer Case Cleaning and Inspection . Replace the range sleeve if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or missing input gear thrust washer	Replace the worn or missing input gear thrust washer. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or faulty planetary differential	Inspect the planetary differential for the following conditions: Loose planetary differential splines to mainshaft splines Loose or faulty pinion gears Refer to Transfer Case Cleaning and Inspection . Replace the planetary differential assembly if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or missing rear output shaft thrust washers	Inspect to ensure the thrust washers are installed. Inspect the thrust washers and mating surface for excessive wear. Replace the worn or missing thrust washer. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or damaged rear sun gear	Inspect the sun gear external gear teeth for excessive wear. Inspect the sun gear to rear output shaft for excessive looseness. Replace the sun gear or rear output shaft if it is worn. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Rear output shaft bearing outer retaining ring	Inspect for the following conditions: Properly installed rear output shaft bearing retaining ring Excessive wear or damage to the retaining ring groove in the rear case half Refer to Transfer Case Cleaning and Inspection . Repair or replace the following components if found faulty: Replace the rear output shaft bearing outer retaining ring. Replace the rear case half if the retaining ring groove is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Lockup shift assembly hub	Inspect the lockup shift assembly hub for the following conditions: The hub internal teeth to inner lockup hub for excessive looseness caused by wear The hub engagement teeth for wear Refer to Transfer Case Cleaning and Inspection . Replace the lockup shift assembly if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .