I'm beginning to see why the frustration exists. Virtually all new up front and the Angry Birds are still abound. To date , no one is able to nail down where the sound originates as opposed to what may be the perpetrator ( front diff or t-case). So , there is no chance that this is caused by the front hub bearings ? Don't know if they were changed. If this noise starts from when to brake is released and continues , with the engine off and front on jack stands , try spinning the wheels with t-case engaged to simulate under load . If this does not produce the noise your hearing , the only safe way would be to run the jeep on a dyno table ( on rollers like a diagnostic run) to be able to have a tech standinding near to isolate where is the noise from. I won't just say its a bearing , but need to be sure . BTW , yes , the t-case and front diff needs to be attended to first before going on. Hoping all is well inside of them .