Im stumped... My truck began losing power while driving one day, 55mph top speed even w/ pedal to the floor. Then about a month later it was 45mph, then 35mph the month after that.... until one day it dropped to 5mph then 0. Now, it wont budge yet starts & runs just fine. what the heck?..someone said it might be the clutch?.... I have no idea where to start? Clutch pushes in, it seems to feel as if it goes into gear, but when you let it out, it does nothing..... no noise, no grinding, no movement,... no nothing. Yet everything else seems totally fine..........