GMC Sierra 3500 HD transfer case issue persisting for 2 months on GMC Sierra 3500 HD

Some GMC Sierra 3500 HD owners report experiencing persistent transfer case issues that can stem from various factors. Even when a code reader does not show transfer case codes, there may still be diagnostic trouble codes generated by the transfer case setup that are crucial for identifying the root cause. Owners have noted that if the transfer case fails to engage in 4x4 despite the indicator light being on, it may signal a malfunction in the transfer case system, necessitating checks of the drive shaft and front differential actuator. Additionally, previous repairs, such as encoder motor replacements or new transfer case installations, could contribute to ongoing problems, potentially leading to rear end issues due to constant hard shifting. Excessive use of RTV during assembly has also been reported to cause oil pickup screen blockage, resulting in transfer case bearing failure. For those unable to resolve the issue independently, consulting a qualified mechanic or dealership experienced with GMC Sierra 3500 HD transfer case systems is recommended for effective diagnosis and resolution.