2004 660, i just bought it. Twice now when giving it some gas from a dead stop there has been a loud grinding noise and a shutter type vibration. When this happens it does not move or barely moves. If i let off the gas and give it gas again it is fine. I have done some reading on here and it sounds like something in the clutch setup. Any thoughts? The two times this has happened it was in 2WD but may not have anything to do with it. So far it is an awesome machine.