f 150 tranny issues
 

changed filter and gasket fluid was very clean small amounts of metal in pan. it will go in reverse and thats it. we were told torque converter does that sound right. ???

There is a first time for everything, but I do not believe the torque converter is the problem, because nothing changes with the torque converter when going forward or backward.
There is a forward clutch that has to be activated for forward and It might be a good idea to verify the MLPS (formally neutral safety sw,) is sending the signal to the trans solenoids. If it is , then we need to get into the trans a little further.

Is this why you changed the filter or did the problem surface after changing the filter?