HELP! Rear End Clunk after shifting & removing foot from clutch

New to Jeep ownership. I can't seem to get it going into the next higher gear without a clunk noise from the rear end. I first thought it was a universal joint problem but they appear rock solid. When in neutral I can turn the drive shaft by hand about a 1/4 inch before a full stop occurrs. Any help in diagnosing the cause of this clunk. Annoying as hell... I've also called dealers only to be told I'd have to bring it in for an inspection. I asked them if this is normal to this vehicle and neither one could give me a difinitive answer. Vehicle is a '96 Jeep Cherokee Sport 4.0 w/5spd manual.