Steering Noise Mystery

[Scott]

My wife has a 2000 Lincoln Continental with 120,000 miles on it. For
awhile, there's been a low level squeaking/rubbing sound when turning
the steering wheel both ways at low speed...intermittently. It sounds like
it's coming from somewhere in the steering column and not down lower
by the wheels. To me, it sounds like a rubber bushing rubbing.

Last night, when the nighttime temperature went from the 50's to the 30's,
it was more pronounced.

I took it to the Ford dealer for an oil change today. They said the power
steering fluid level is okay and suggested it may be one or more ball joints
being worn (around $100ea plus labor). The tires have been wearing
unevenly, and they're near the end of their life. A few months ago, they
checked the alignment and said it was okay.

When they finished, I drove the car out....and there's no more noise when
turning. It's as quiet as the day it was new.

I suspect they raised the car on the lift to check it out the ball joints and then
lowered it again. So what was it about raising and lowering the car that
stopped the squeaking?

I'm not complaining. I'm wondering if that gives a clue about what was wrong.

Thanks!
Scott