1989 240 wagon.

The car has become progressily worse. While driving, when you turn the wheel, it feels like it takes a couple seconds for the body to
catch up. It's hard to explain the problem, but it's almost like it swims when you turn and as high speeds 60+ it feels very unstable.

I'm assuming it could be the sway bars, I don't know much about them, but from what I've read, they keep the car fromwondering on cornering.
Possibly the bushings?

 

Have the steering Tie rods checked.
It could also be the bushings but I would have a full suspension check done.

 

rear trailing arm bushings was the culprit.

 

Glad you found it.

 

Because of this thread I decided to do some hands on checking of my rear suspension. The torque rod bushings were completely shot, the panhard rod bushings were at least there, and the trailing arm bushings were ok, Iguess (Not easy to check those without a long prybar or at least unloaded)......So I ordered a complete bushing replacement kit off e-bay. Can't hurt with 201K miles on her. Thanks for the idea gents!!

Dale