Excessive wear of outer edge of front tires

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Hi, There was a oil leak in rack & pinion and I was asked to get it replaced. I got it done and thereon there have been two issues. One is that on very slow turns there is a screeching sound from tires(more on a right turn)like as if I am doing one of those skid turns. Second issue is that outer edge of the front tires (have done 1000 miles only) totally wore off and I can see the steel wires after driving 425 miles from Niagara to NYC.The left tire's condition is worse than the right tire. Any suggestions what may be wrong and how much will it cost in Eastchester to get it all right. Thanks