Transfer Case Clunk in 4HI

WARNING: This page is about a different car, the 2007 Isuzu i-370, 2007 GMC Canyon, and 2007 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.

Cause	Correction
DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer case while in the 4HI 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 Transfer Case Fluid Replacement .
Input shaft thrust bearings	Inspect for worn or missing input shaft thrust bearings. Refer to Cleaning and Inspection . Replace the thrust bearings, as required. Refer to Transfer Case Disassemble and Transfer Case Assemble .
2/4 Wheel drive synchronizer assembly	Inspect the synchronizer for the following conditions: The synchronizer hub for not being press fit on the rear output shaft splines The synchronizer sleeve to the synchronizer hub for wear The synchronizer sleeve to the drive sprocket engagement teeth Refer to Cleaning and Inspection . Replace the synchronizer assembly, if faulty. 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 .
Range sleeve	Inspect the range sleeve for the following conditions: Worn engagement teeth Worn internal splines Refer to Cleaning and Inspection . Replace the range sleeve if worn. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Front output shaft yoke	Inspect the front output shaft yoke for the following conditions: Yoke flange nut loose Yoke loose fit on the front output shaft Replace the yoke flange nut if loose. Refer to Transfer Case Output Shaft Seal Replacement - Front . Replace the yoke if the internal splines are worn. Refer to Transfer Case Output Shaft Seal Replacement - Front . Replace the front output shaft if the splines are worn. Refer to Transfer Case Disassemble and Transfer Case Assemble .