I just bought a 95 320i coupe which is in great condition and a dream to drive (you just gotta love that straight-6

). The only thing is that 3 times I have experienced a loud "chunk" noise and jolt when going into 1st gear and releasing the clutch. I figure I'm not engaging the gear fully and it's dropping out. It's pretty loud and I usually step back on the clutch, reengage 1st and everything's fine.
Anyone have an idea what this could be??