COramprat said:
did you hear anything snap when you hit 3rd? It may be an input or output shaft, possibly an exploded clutch disc. I'm assuming you have tension on your clutch cable, so that would rule a snapped cable out. I'm not sure if this is how you check for a snapped shaft, but I would put the car on level ground, jack up the rear/secure the front wheels, put the car in gear, then crawl under and see if i could spin the drive shaft. I'm not a mechanic though, maybe someone else has some input for you