The Taurus and Sable can not be aligned for edge wear on the tires. That angle is called "camber". It is the inward or outward tilt of the tire as viewed from the front or rear of the car. It is set at the factory and is not adjustable. Ford is the only company that does that to you. As the springs sag with age, camber changes, hence the need for periodic alignments. What IS adjustable on your car is "toe". That's the direction the tires are steering. If one or both tires are misadjusted, it affects "total toe". That is the sum of both front tires, and it will always affect tire wear on both tires equally. That means both tires will wear on the inner edges or the outer edges, depending on which way it is misadjusted. That is separate from camber wear which only affects that one tire.
Most cars have gone to bolt-on front wheel bearings. Chrysler started using them in the late '80s. GM has always used them. They are rather easy to replace and doing so will not affect the alignment. If your car still uses a pressed-in bearing, replacement is rather involved. With the right tools it can be done right on the car without removing the spindle. Some people still remove the spindle so they can press the bearing out on a hydraulic press. It is always possible the parts don't go back together exactly as they were but it shouldn't be so bad as to cause tire wear that wasn't there before.
There's a simple clue to determine if the alignment was affected. Due to the geometry of the steering linkage, if camber was changed from the bearing service, toe on that wheel will also change. That will cause edge wear on both front tires but if it's bad enough to do that, it is also bad enough to cause you to have to turn the steering wheel off-center to keep going straight. If your steering wheel was straight before the bearing service and it is straight now after the service, the alignment did not change.
Keep in mind you are going to have less than perfect tire wear. It's "the nature of the beast". 1980's Escorts were WAY worse. If you got 15,000 miles on a set of tires, you were doing pretty good.
Tuesday, November 23rd, 2010 AT 1:21 AM