1998 DeVille has wobble in rear wheel. Mechanic says knuckle upper pivot bushing is bad. Problem noticed at 50,000 miles when we got the car and now 90,000 miles. Wears out tire. The price for a new knuckle is $646. Anyone heard of this problem? Know of a place to find a bushing only?

It is a common problem on our cadillacs. Unfortunately it is a very expensive part as you see. You can find just the bushing but it is very hard to install and you need a special press with correct adapters to install it properly.