Happy 4th!

This sounds like a known Volvo high mileage problem! Question: Are you saying that the steering stiffens and loosens as you rotate the steering wheel? Also, does it ever “stick” momentarily?

I had those issues with both my 90 240 and 95 850. If that is your problem, then that indicates exterior corrosion and possible rust buildup on the outside of the steering shaft u-joints. Not familiar with the steering shaft design on your model but my guess is that is the same as the 850 and 240. Meaning that there is an upper and lower u-joint on the shaft.

Typically it is the lower one that connects to the steering rack that starts to seize up because of its exposure to road grime, salt etc. If this is your issue then a possible fix is to rotate your steering lock to lock for a few minutes while spraying the u-joint liberally with WD-40. A couple of treatments might be necessary. You can also follow up with moisture resistant grease if so inclined…
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Will I buy another Volvo??? We'll see....