I bought my son his first car - 1987 Mazdz RX7 non turbo. He really wanted to learn to do the work himself , but .. we had a mechanic come out and help with the clutch job and re-install the tranny. After I finished re-filling the tranny with 75-90 gear fluid,I took the car off the jack stands and pushed it back down the driveway, out of the garage today.
I started it .. started quickly after sitting for 2 months. When I went to move it over to the side further, engaged the clutch, shifted into 1st and when I let the clutch out slowly, the clutch grabbed as if I popped the clutch, lurched forward. I heard a loud clang and felt as if something broke loose. When I pushed the clutch back in and hit the breaks, the car acted as if I had the clutch out, still in gear moving forward and stalled as I had the breaks on.
I shut down and called the mechanic to let him know something is not right.

Any ideas, suggestion would be helpful. What we might have done wrong .. etc

 

Maybe the throwout bearing came off of the clutch fork? Hard to say, but it should be obvious once the tranny is pulled again.

 

If the car cannot shift when the car is running but the car can shift when the car is not running then you destroyed the pilot bearing. Most likely when putting the trans back on.