I have an 88 chevy half ton 350 w/ 5 speed manual trans. For the last couple of days I have been hearing a sort of chattering coming from the transmission. I noticed that it was only making that sound when the clutch pedal was depressed so I started just putting the truck into neutral when I stopped at a light or in traffic. Today as I was leaving work, I did the same thing, only a couple of times, when I went to put the truck back into gear, it didnt want to go, I didnt want to force it for fear of what would happen, I just started trying to find a gear, and finally got it into third. Then I was able to shift into first, and then on through the gears like normal with out any problems, It happend a couple of more times on the way home, but only as I was at a stop, and shifted from neutral into gear, can anyone tell me what the problem is, I suspect its the throw out bearing, but Im not sure. any help is appreciated, thanks