Scirocco Register

In the last few days a new problem has come up with my 87'mk2.
When I put the car in first and take out the clutch there is a rumbeling feeling and the car jumps a bit for 1/2 second, when the clutch is all out it works fine. until I change to second gear, same problem there.

gearbox or clutch?

Have you checked all the engine and gearbox mounts?

It could also be the clutch struggling to get grip until the car is rolling - worn clutch

It's unlikely to be anything to do with the gears/gearbox otherwise the problem would be constant whilst moving.