how do you know it stays engaged?does it show it going into 2 wheel on the switch?
AUTO ALL WHEEL DRIVE
is your problem that the drive shaft from the case to front diff is always turning?what is your complaint?noise?ect...?
with All-Wheel Drive (NV 136) Transfer Case (RPO NP4)
This bulletin is being revised to update the correction information. Please discard Corporate Bulletin Number 99-04-21-005D (Section 04 - Driveline/Axle).
Some customers may comment on a vibration (shudder) during tight turning maneuvers on dry pavement at vehicle speeds less than 8 km/h (5 mph).
This condition may be caused by a slip-stick of the clutch plates in the transfer case clutch pack. On 1999 to 2002 models, the preload that is designed into the clutch pack may contribute to the condition. In addition, contamination of the fluid may interfere with the friction modifiers.
Flush and replace the transfer case fluid on affected vehicles using the following procedure and the part number listed below.
Perform the following diagnosis prior to flushing and replacing the transfer case fluid in order to properly identify the shudder.
HAVE ALREADY DONE THIS PER SERVICE BULLETIN ABOVE - NO CHANGE