First off I admit I am not a transmission/rear-end guy. I know what I know from experience. BUT seems lots of these Silverados have had the same problems resulting in the two piece drive shafts. When I say service, obviously I didn't make myself clear because changing the filter, fluid and seals are called maintenance in my book not servicing. Anyway dude, from a Texan to another Texan I wish you luck, but yeah have someone you know and trust look it over.