Transfer Case Clunk in 4HI

Cause DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer case while in the 4HI range only. 1. Compare the noise to a similar vehicle and see if a normal condition. 2. Identify the source of the noise using chassis ears and refer to the appropriate service manual section. 3. Note specifics such as when the noise is present (2HI, 4HI, OR 4LO). 4. Note if the noise relative to vehicle speed, is noisy on turns, during acceleration, stops, or other specifics. 5. If the source of the noise is the transfer case, inspect for the correct fluid level. 6. Inspect the drain plug for large metal deposits. Small metal flakes and fine metal dust on the plug magnet are to be considered normal. Review the Symptoms - Transfer Case and perform the necessary inspections.	Action
Tire pressure uneven	Note: A clunk condition that occurs when performing slow speed turns in 4WD may be caused by low or uneven tire pressure. 1. Set the tires to the recommended vehicle tire pressure for evaluation to see if the noise goes away. 2. Upon completion of the test, reset the tire pressure to the correct pressure as recommended on the tire.
Transmission or transfer case mounts loose or damaged	Repair or replace the mounts as required
Propeller shaft center support bearing worn (as applicable)	Replace the center support bearing as required. Symptoms - Propeller Shaft
Propeller shaft universal joints worn	Replace the universal joints as required. Symptoms - Propeller Shaft
Front axle actuator shift noise	Note: When shifting from 2WD-to-4WD or 4WD-to-2WD, the front axle actuator may be heard engaging or disengaging and the axle internal components shifting. This is to be considered a normal condition. Shift from 2WD-to-4WD and from 4WD-to-2WD to determine if the noise source is the front axle to determine if this is a normal condition.

Cause	Action
Suspension components worn	Replace the suspension components as required. Noise Diagnosis - Front Suspension or Noise Diagnosis - Rear Suspension
4WD gear noise	Note: A growl or clunk that occurs with vehicle in 4WD at low speed in a tight turning radius situation may be caused by the gears and chain and is to be considered a normal condition and an operating characteristic of a 4WD system. Operated the vehicle in 4WD performing low speed left or right turns to confirm a transfer case gear noise.
Transfer case planetary carrier gears worn	Note: A clunk in 4HI noise that increases in 2HI only may be caused by worn or damaged planetary gears and ring gear damage. A clunk in noise that occurs in either 2HI or 4HI may be caused by worn planetary gear needle bearings or shafts. A clunk that occurs in 4LO may be caused by worn planetary gears or annulus gear. Repair as required. 1. Inspect the following: Chipped, bent, or deformed teeth Planetary gear needle bearings worn Planetary gear thrust washers cracked or missing Seized or binding planetary gears High/Low Planetary Carrier Cleaning and Inspection 2. Replace the planetary components as required.
Transfer case rear output shaft rear bearing retaining ring- incorrectly installed	1. Inspect for the following: Improperly installed rear output shaft rear bearing outer retaining ring. The snap ring is to be installed completely into the OD groove of the bearing. Excessive wear or damaged retaining ring groove in the rear case half 2. Repair or replace the following components as required: Properly install a new rear output shaft rear bearing outer retaining ring. Replace the rear case half if the retaining ring groove is excessively worn. Transfer Case Disassemble and Transfer Case Assemble