I won't put up a pros/cons list, but it is very advisable to replace parts for both sides of the axle, if the part is responsible for steering, suspension, and safety of the vehicle and its occupants.
So, if you replace a tire, you should replace both tires on the same axle. It also advisable to replace tire with the same thread pattern for all four tires for driveability issues. Same thing goes with ball joints, tie rod ends, struts, brake system, and the list goes on.
To answer your question, as involves steering and suspension, you will need to replace ALL tires, or at least put two new ones in the rear, and put the two old good ones in the front. As you damaged the tires, I suspect that you also have some damage to the wheels, as well. Check them out before putting the new tires on them.
But it is your call, you can replace just the damaged parts only, but keep in mind that your vehicle won't perform safely.
Sunday, March 29th, 2009 AT 7:31 PM