First, what year 850? The reason I ask is a 93 has a strange size belt. Your belt should be a 6PK1743 if you have anything but a 93.

When we drive in circles, it is very near full lock, hitting the stops on occasion. I often wonder what the people in the houses at the dead end think...

A few other things that could affect it are: the AC compressor, when the defrost is on, the compressor is on, if the compressor is cycling on and off, it too will affect belt tension. Also, the tensioner (obviously) can affect tension.

The few racks that we have had go bad had varied symptoms, but usually, the symptoms are one, any, or all of:

a bad "spot" in the rack...where it kinda catches and then frees.
leaking so significantly that you can't rationalize adding fluid,
tremendously easy to turn one way, tremendously difficult to turn the other,
and "one" that actually "suddenly" made grinding noises and broke internally.

What you described just doesn't seem like rack to me, but stranger things have happened...like the last one above...

Chris