My wifes van has had new struts, sway bar bushings, sway bar links, four rack and pinions and going on the 3rd set of tires at 82k miles. Had it alined and checked by different shops, tires balanced everything is good I am told. Why are the tires wearing like this then? When braking for cruising speed the steering wheel shakes pretty bad. New brakes and rotors too which helped some but the shake will be back. Help.