ok here goes; i posted in the other powertrain forum but have not had any help. i have a stupid problem with a clinking sound echoing from my driveshaft on my 1989 F150, i have had this problem for 3 years. i have changed universals, tightened the rear axle pinion nut, changed the exhaust, swaped the rear end for a posi unit. inspected the leaf springs for cracks and looked up and down for anything else. the noise originates from the driveshaft and i am thinking that it is comming from the pressed ends of the shaft itself; i am guessing this would be called a 3 piece driveshaft? anyway i am looking for anyone who has had experience with these driveshafts and wether or not those clamps which are pressed on can loosen and cause a sound like that. my other thoughts are that it could be comming from the tailsection of the transmmision, it is the mazda m5od. does anyone have any thoughts... the sound only occurs during takeoff, and sometimes de-acceleration, i hear it most when i am towing my 18ft boat or trailer.....