Transfer Case Clunk during Acceleration and Deceleration

Cause	Correction
DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer case while in the 4HI mode. 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 .
Excessive clearance between the slip yoke and the rear output shaft	Inspect for the following conditions: Worn slip yoke splines Worn rear output shaft splines Repair or replace the following components, if faulty. Replace the slip yoke, if required. Refer to Rear Propeller Shaft Replacement . Replace the rear output shaft, if required. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Excessive clearance between the slip yoke and the rear bushing	Inspect for the following conditions: Worn rear bushing Worn slip yoke bushing journal Repair or replace the following components, if faulty. Replace the slip yoke, if required. Refer to Rear Propeller Shaft Replacement . Replace the rear case half if the rear bushing is worn. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn high speed teeth on the range sleeve	Inspect for the following conditions: Worn high speed teeth on the range sleeve Worn or missing input gear thrust washers Refer to Transfer Case Cleaning and Inspection . Repair or replace the following components, if faulty. Replace the range sleeve if it is worn. Refer to Transfer Case Disassemble and Transfer Case Assemble . Replace the thrust washers, as required. 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 the 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 .
Worn or damaged front sun gear	Inspect the sun gear external gear teeth for excessive wear. Inspect the sun gear to drive gear teeth for excessive wear. Replace the sun gear or drive gear 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: Proper installation of the rear output shaft bearing retaining ring Excessive wear or damaged retaining ring groove in the rear case half Repair or replace the following components if found faulty: Properly install a new rear output shaft bearing outer retaining ring. Replace the rear case half if the retaining ring groove is excessively worn. Refer to Transfer Case Disassemble and Transfer Case Assemble .