F150

So against my better judgement I got a fird
f150 stepside it started shaking bad once
you get to 50-55mph took it to O'Reilly and
they checked it code came back to a bad
coil pack ( found out my truck has no spaek
plug wires... Grrr coil packs)  so the coil pack
got replaced truck ran fine for about 4
weeks well it's back to doing it again this
time with the truck acting like it wants to
throw the trans out for under it and wanting
to die took it back to O'Reilly they checked it
and it's now saying left front?  Speed
sensor?  Symptoms don't match to a speed
sensor.  So once you get to 50-55 it shakes
and vibrates like crazy but then it's doing it
at any speed but it seems like once the truck
is warmed up and following another vehicle
it calms down and isn't so bad?  Wth?  So is
it just possessed??