Transfer case is in........doesnt want to go into 4Lo everytime. I think this is due to dropping the transfer case onto my shoulder and possibly damaging the servo motor FML. I also installed a new transmission mount while I was at it Today, was new 4wd switch in the cab, fuel filter, rear diff fill port re-seal, exhaust gasket between the cats and muffler(apparently, the gasket that came with my Magnaflow cats was a cheapo). Mechanically, the only thing left is the oil pan gaskets and rear main seal! Then new paint and carpet........it will be a new 99 Yukon again!