The key is to just get the car safely up with the rear wheels suspended so you can turn everything. Just start turning and shaking things and you'll probably find the culprit.

Everything on the 123 car is pretty easy to replace. I put a front flex disk on my 124 car a few weeks ago and had to drop the exhaust and stage a few other battles to complete the job. One of the real beauties IMHO about the 123 is its simplicity of maintenance and repair.

Good luck,