93 taurus shake in steering

i got a 93 taurus, 3.0 automatic, GL... about one month ago i had the shake in the steering and found the right front tire had some damage to it( the wear was where the metal was coming through in one spot about 3 in. long).. i changed the tire and the shaking steering went away.. i figured that this was the problem- a belt in the tire was broken and this was causing the shake.. well now with a new tire, balanced and all the steering wheel has a shake in it when applying brakes or when accelerating... i now think that there is mechanicl damage and this is what caused the tire to go bad in the first place.. before this happens to the second tire has anyone got any suggestion of what to look for.. i think it might be in the right fron as this is where the tire(bad one) was located..... thanks for a reply....