Im extremely down, i got the car running after sitting for 4 years and got it driving and then it started knocking. Definitely not coming from the engine bay. I put it on blocks and spun the tires from 1st to 5th. The sound got progressively worse. Whats strange is if i shift it smooth and nice it doesnt seem to make the noise. I put my hand on the bell housing and it seems to be coming from there but I'm not sure. My friend said it might be play in the crank shaft. I really can't tell and i can't find a thread where someone experienced this. Please help! I'll post a video.

https://youtu.be/DH5Hiu5siGE

 

Definitely sounds like a problem inside the trans. Pull the trans and check out the clutch and throw out bearing, etc. Might need a clutch kit or perhaps a trans rebuild. These are really easy transmissions to remove. Just pull it and see what your dealing with.

Make sure that's not a u-joint failing in the driveline first.

GD