Are you shore it's the transfer case and not a clutch plate problem,
They will make a noise like the gearbox is ratshit or in your case the transfer case,,
Give Chris Meek a ring at Meek Automotive 0297691586 and discribe your problem..
Also see this link,,
http://www.4gtuner.com/topic/19120-off-throttle-rattle-noise-in-3rd-and-4th-gear/page__p__239542__hl__%2Bclutch+%2Bnoise__fromsearch__1#entry239542
