You problem could be corrosion on the steering shaft lower u-joint. Years of exposure to rain, snow, salt, sand etc. cause this. This caused the heavy steering on my 850.

Actually, I think you only need to be concerned with the lower one. It is easily accessible behind the engine from the top of the car. Remove the preheat hose that runs from the air filter box to the exhaust manifold and you will see it. You can spray/lube the upper one too, but it is inside the car near the firewall so it is unlikely to be a problem.

All I do is spray the u-joint with WD-40 as I work the steering back and forth almost lock to lock for a couple of minutes. This might take 2 or more tries to free-up the u-joint. Reapply as needed. FYI - There is a special lubricant/grease? for u-joints that I haven't tried which is supposed to be better than WD-40. I had this problem on my 240 first, someone on the RWD forum suggested trying this. Has worked for me on 2 cars...:)

Changing the PS fluid is a good idea too. That stopped a slow leak in my rack.

Good Luck,
Jim