I have a 1993 F150 4x4 with a 5.0. When I am accelerating and i quickly let off the gas, there is a loud clunk. I also hear this clunk when i let the truck coast and engine break then put my foot back on the pedal. What is this clunk? Its driving me crazy.

 

Real good chance it is a driveshaft universal joint. Service immediately!

 

Take a look at the u-joints, that's a possibility.

 

After checking the u-joints, check the transmission and motor mounts.

 

and carrier bearing if you have one

 

Everyone says check the U-joints. What am i looking for?

 

both ends of the driveshaft. see if they are loose.

 

i find it helps to jack up the rear end while checking the U joints on the drive shaft.

 

There is a TSB on the tranny mount. Common issue.