2000 silverado Z71 driveline vibration
 

I have a 2000 Z71 that has a driveline vibration when pulling out. the truck has all the classic symptoms of a bad U Joint. It has 155k on it and I am hearing that it may be a Chain in the Transfer case instead. The family mechanic can not get the bolts out to replace the U joint so that will have to wait until I get back to the states. Has anyone else heard or had issues with this transfer case chain?