[alanwoodieman]

1941 pick up with 3:78 rear gears, had an unusual noise in rear end, owner thought it was trans but could not be convinced it was not. changed trans, noise was still there, turned out the pin in the sleeve coupler on drive shaft had broken and a piece of it became wedged between torque tube and pinion nut and when he backed up it spun the pinion nuts off the pinion. it was the weirdest thing I have seen in over 46 years or working on these Ford!