Vibration after breaking, but only in drive

The vibration begins when I stop after applying the brakes (after driving a bit), and then the vibration stops only if I put it into neutral or park or begin accelerating again. The engine mounts have been checked, the car has been tuned up (right after the vibration began) and the cv axle was changed (again) to a better one. I haven’t noticed and the mechanic has not said anything about the tachometer needle. I’ll remember to look today when I take the car out.
There has been mention of a faulty torque converter, but I understand there’s no real way of checking this without taking out the transmission. Any ideas on this?
Thanks!