I bought a 2000 Jeep Grand Cherokee Laredo 4.7 4wd a year and half ago. It has 271,000 miles on it. It runs great. When I bought it, it had 245/75/16 tires on it. With no problems. Well I got a good deal on 4 used tires and rims. They are the size that was supposed to be on here 225/75/16. Now occasionally the whole Jeep shakes violently. So bad that I have to stop the vehicle. Any ideas on what the problem could be.