Steering instability

I recently took my 1990 Ford Taurus to a garage. Driving it is unpleasant, or more accurately, steering it. Something going on in the steering wheel. Odd internal movements. The garage said there were worn parts. They replaced the rack and pinion, both outer tie rod ends, the subframe bushings, and the subframe itself. Still has the same problems. But, the steering itself is stable. I do not understand this. I took it on the Interstate, got it up to 75mph. Removed my hands from the wheel and car continued travelling in a straight line requiring only very slight pressure at intervals to correct for small drift - and that was despite high wind gusts.

So, what is with the sensation in the steering wheel? It feels like it is jerking at intervals. No noise associated. End result is that I do steering correction that isn’t always needed.

What is going on? I don’t drive this car much, but it used to handle very nicely. Certainly got a big enough repair bill that didn’t seem to address the problem.

This could be wheel bearings or ball joints or a broke upper strut mount. The wheel bearings and the ball joints are easy to check so I will assume that the mechanic checked those and could not find the problem.

About the only way to check the upper mount is to remove the struts. One clue would be if the jerking occurs on rough roads.

A failing power steering pump?

Open your power steering reservoir and remove and discard it’s contents with a turkey baster.Peer into the reservoir with a flashlight and see if the intake filter screen in plugged up with hose particles and ‘stuff’…If so, remove and clean the reservoir, reinstall and refill with fresh fluid. Most Fords are happy with ATF. Start the engine and turn the steering wheel lock to lock several times and recheck the fluid…A plugged filter screen will starve the pump and cause all sorts of steering problems…

Good suggestions here, but don’t forget the REAR wheels. A failing bearing can cause that erratic jerking that you describe. Any drag on a rear wheel will present as a steering input.