I have a '90 F250 w/ 460 & E4OD trans. Whenever it shifts into O/D with a bit of a load, like under acceleration, the truck shudders for a second or two and then makes the shift. Is this an indication of problems requiring major surgery on the near future? Any ideas are appreciated.

 

the first thing i would try before i thought about surgury is fluid/filter change. has it been over 25,000 since the last. If you carry heavy loads this will require a shorter fluid/filter change intreval.