shake with ac on

[HSV472]

when you take of from a stop get to about 2500 rmp starts to shake
fell like it coming from the motor
pretty big shake
only when ac is on doesnt do it any other time
also car is a vr clubby

[Brett_jjj]

Maybe harmonic balancer.Get a screwdriver behind it and lever it to see if it has any movement or play.It should have none.And have a good look at it with the engine idling.It should be running true with no wobbles visible.