Transfer Case Clunk During Acceleration and Deceleration

WARNING: This page is about a different car, the 2017 Cadillac ATS. 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 within the awd system or within 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 manual section Note specifics such as when the noise is present. 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 Loose Or Damaged	NOTE: A clunk noise that is heard during acceleration or deceleration may be caused by a loose or damage propeller shaft. Inspect and repair the propeller shaft as required.Refer to Symptoms - Propeller Shaft .
Transfer Case Fluid Level Low	NOTE: A clunk noise that is heard during acceleration or deceleration may be caused by a low transfer case fluid level and clutch pack slippage. Fill the transfer case to the correct fluid level and retest.
Clutch Pack Noise	NOTE: A shudder or bindingtype noise when awd is engaging or disengaging may indicate worn clutch pack friction discs. Disassemble the transfer case and inspect the clutch pack for worn components. Replace the clutch pack assembly and reprogram the transfer case control module as required.Refer to Transfer Case Control Module Programming and Setup