I have a 1990 LX 5.0 and my power steering pump is whinning when I turn. The fluid is full so I'm thinking the pump is on it's way out. How hard is it to switch it?
It is not very hard to switch but it will require you to rent a puller for the pulley. It is pressed on and has to be pulled off and pressed on the new pump.
Gooch, I would not ditch the pump just because of the whine. Like ZC said, most of the new parts store units whine too. I would wait for real issues (bad noises, bad bearings, pump leaks, etc) before replacing it.
You might have just as good a' luck with thoroughly flushing the system. When I replaced the steering gear top to bottom, I ran synthetic fluid meeting Type F requirements and i think it helped. I would probably do that instead, based upon what you have said.
A guy at work said he reduced the whining by adding some friction modifier to the reservoir. It originally came out for LS and Aviator steering noises. I didnt hear his car before he added though but it definitely wasnt loud after he added it.