The bearing is part of the upper strut mount. It is never available separately. The mount IS available by itself. I suspect you're thinking you have to buy the complete strut, spring, and mount as an assembly, but that is the less-common way of buying the parts. Those complete assemblies eliminate the need for a spring compressor, and the new springs restore proper ride height which restores balanced braking front-to-rear, and improves steering control and handling.
Regardless of whether you replace just the mount or the whole assembly, the car needs to be aligned after the repairs are completed.
Wednesday, May 6th, 2015 AT 8:11 PM