Had the same problem with my 2004 Altima
They replaced the U-joint in the steering - it cannot be lubricated, has to be replaced (did notice when it rained, the steering wasn't quite as tight, weird).
Steering U-Joint may be your answer - common problem in Altimas. Not sure why all these mechanics aren't thinking of it - it's the first thing my mechanic thought of after telling him my fluid was OK and there was no noise from the steering pump.
Tuesday, October 12th, 2010 AT 3:41 PM