I have a 1992 Jeep Cherokee with 177,000 miles. I have started to do some wheelin' in the past few years and I drive it over the mountain pass to and from college a lot. So I have this noise that has just developed in the past two weeks. It is an annoying chattering sounding noise. It increases with the speed of the vehicle. It sounds like it is coming from either of my differentials or my transfer case/transmission (god forbid). In a way it sounds like there is a loose metal part that is being thrown around in a metal case relative to the speed of the vehicle. Sort of high pitched too. My transmission clanks loudly evey time i put in drive as well. Any help would be greatly appreciated!