I have a 2000 Ford Focus LX, manual. About a month ago, one day, I was stopping in front of a red light. When it turned to green, I shifted into first gear as usual, lifted my left foot a little bit, then pressed the accelerator, and----------"BOOM!" a huge sound from the hood. And the stick was like being strucked by something and jumped back to neutral. I thought I didnt shift down to the end (though I never had this problem), so I tried once more. And again it jumped back into neutral. I had a little bit problem with the first gear ever since I got the car. It would make very unpleasant noise (as if the gears were grinding each other) whenever I tried to shift into first. But I thought it was not quite a big deal, so I didnt even pay attention. Apparently I was wrong.
Two weeks ago, I put this car to a friend of mine, and he suggested it would be the clutch, so I replaced the whole clutch. However, it didn't fix the problem. Now I really have no idea what to do next. Ford dealer asked for $800 for simply check the transmission (it might be $2000 for install a new one). So, anyone has any suggestions, or similar problems? Thanks in advance.