Transfer Case Banging Noise

WARNING: This page is about a different car, the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, and 2018 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.

Cause	Correction
A faulty internal transfer case component that causes a loud banging noise in the transfer case. Compare the noise to a similar vehicle to see if a normal condition. Identify the source of the noise using chassis ears and refer to the appropriate service information. Note specifics such as when the noise is present (2HI, 4HI, or 4LO). Note if the noise is relative to vehicle speed, is noisy on turns, or other specifics. If the source of the noise is the transfer case, inspect for the correct fluid level. 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.
Transmission or transfer case mounts loose or damaged	Repair or replace the mounts as required
Propeller shaft center support bearing loose or damaged (as applicable)	Replace the center support bearing as required. Refer to Symptoms - Propeller Shaft .
Propeller shaft universal joints worn	Replace the universal joints as required. Refer to Symptoms - Propeller Shaft .
Suspension components worn	Replace the Suspension components as required. Refer to Noise Diagnosis - Front Suspension or Noise Diagnosis - Rear Suspension .
Transfer case rear output shaft bushing worn	NOTE: A worn bushing and or slip yoke may also create a clunk type noise and may be indicated by a leaking rear output shaft seal. Replace the rear output shaft bushing and propeller shaft slip yoke as required.
Transfer case drive and driven sprockets worn or a stretched chain causing a chain jump condition	NOTE: A chain jump condition may cause a banging noise and can only occur with the vehicle in 4WD. A chain jump condition may be caused by water intrusion into the transfer case and deterioration of the transfer case fluid. Water intrusion conditions may occur in extreme off road conditions or in situations where under-vehicle power washing occurs. Inspect the oil for water intrusion and/or fluid discoloration and contamination. Inspect the vent hose for proper routing and connection to the transfer case. Inspect for damaged internal components. Refer to Drive Chain, Drive Sprocket and Driven Sprocket Cleaning and Inspection . Replace the chain and sprockets as required. Refer to Transfer Case Disassemble and Transfer Case Assemble .