I replaced mine, and no there is nothing too surprising in doing the rack and pinion, took be about six hours. Just be sure that you get the alignment done afterwards. As I mentioned before I have an 02 and an 03 and replaced both rack and pinions already, but to answer your question no it is not normal for them to go bad this quickly. I had to replace the power steering pump also, on the 03, it was whining also.

 

42000 .. your lucky, try doing under 10,000. Mine went around that, dealer wanted me to drive it 12hrs to them to replace it LOL morons.. i barely got it to the shop. But they did replace the whole unit, mine came with new tie rod ends, so i didnt even need to get an alignment. Been fine ever since.