Ford Fusion wheel judder

Moving off from standstill at T junctions, I get a loud sound from the front left or right wheels. The sound is like a jerking of the wheel (as though it is slipping and not gripping). Sometimes I'll get wheelspin if I put too much power on, but it seems to me that in normal driving and not trying to do the 'boy racer' thing, this juddering happens too easily. I've reported it to my dealer, and the mechanics have road-tested the car and found nothing, but there is a problem and I'd like to know if simply down to driving technique or something more substantial.