I just bought a '97 4x4 with the 4.0 and for some reason from about 45/50 up till 80 when you barley just have the throttle depressed there is a ominious rattle/noise coming from what seems to be the tranny. As i increase in speed the range that it rattles increase untill 80 then no matter where the throttle is the truck rattles from it... it is really wierd never experienced it before in any other vehicle i've owned and it does not seem to affect the performance of the vehicle when i'm accelerating(considering once i push the pedal past that point the rattle/noise goes away). Any ideas???