I have a 4x4 f-150 with a 4 speed in it and It sounds like it's falling out of gear. The stick is firmly in place but it grinds like it's out of gear. this only happens if I let off the gas in 2nd, 3rd, or 4th, if I keep steady throttle it does not happen. I called every transmission shop I knew of and they all said they would not work on it. Now, one kind transmission mechanic here in Ohio says that there is a e-clip or a snap ring that sits on the side of a "pilot" gear on the side of the transmission next to an inspection plate with six bolts. He says that that if i open it up and can move that gear forward or back then that clip is gone. He says it's quite common on these older transmissions. Does any of that sound like my problem? And if this might be it, then how do I fix it? Help!