OK. I don't know much about modern tranny design but think this way, when you are at a stop, your engine is revving at 700RPM and your wheel is not moving. That discrepancy must be handled by the tranny. some parts in the tranny are translating that axle coming from engine that's moving at 700RPM, and the drive axle going to the wheel that's not moving(because the wheel's held by the brakes). Shouldn't there be a clutch or something in the tranny that's grinding this whole time?