hi my name is joe and i have a 1990 f350 with 78k miles. i bought the truck few months ago and was not been used for about 4 years.i have done all neccessary service maintanance but the problem i'm is that, sometimes the transmission shifts aggressively. especially from 1st to 2nd and to 3rd and 4th is not that bad.now this happens on and off. like it will shift hard for about 400mls of driven and go back to normal shifting for maybe 250mls of driven and on and off.i also experience medium shaking or jurking when changing from 2nd to 3rd and from 3rd to 4th.I will appreciate if anybody has an idea what could be the problem.