Stiff steering '97 328is

[Sundancer]

My steering has become so stiff that I sometimes have to use both hands to return the wheel to center. I've taken it to 3 (!) dealers, and got 3 different diagnosis...1)the rack's seals are shot allowing fluid to pass, so no power assist, or 2)the power steering pump is shot, or 3)the nut on the steering arm is out of adjustment. The car has 250,000km on it, had a 4 wheel alignment after trailing arm bushings were replaced in the rear and two tie rods were replaced, all work by dealer.(about 20,000 km ago). The fluid was down, and has been topped up. I'm a little reluctant to give it to a dealer when they seem to be guessing..anyone have any ideas?

Any help or advice would be greatly appreciated.

[winfred]

does it steer any different with the engine off? i've seen the shaft snap on the pump, if that's not it it's possible that the rack is dead but usually they leak out of the side seals and fill up the boots with fluid

[Sundancer]

does it steer any different with the engine off? i've seen the shaft snap on the pump, if that's not it it's possible that the rack is dead but usually they leak out of the side seals and fill up the boots with fluid

Brilliant : ) steers easier, but not much with the car running, the boots are dry, and do not appear to contain fluid. I assume the pump either works or it doesn't, so it must be the rack...or this "nut" theory...