Get under the front of the car, even without raising the car. You will see a "tube" that connects both wheels. Find an angle where you can look at the rubber bushings holding this "tube" to the frame. If they are old and crusty, that is you problem. If you can shake this tube/sway bar you may be able to reproduce the noise (if that is your problem). Of course the ideal situation would be checking the underside of the car on a lift and visualize the whole front end and then start pushing, pulling, shaking, etc.
Good luck!

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J.H.
'86 300E