We just took in a 2001 Grand Marq with just shy of 170,000 on the clock. Super clean old man’s car, runs great… I took it for a test drive with it today, and I noticed the steering does not return to center after a turn… It seems to stop at about the 1/8-1/4 turn mark, and you have to manually have to turn it back the rest of the way. It makes for some odd feeling driving… Now the car has already been thrugh our shop, but they did not see any problems. The tires are like new, and otherwise it runs great !!!
The first thing I would suspect is that something is bent and affecting the alignment; probably in the caster.
After that a possible steering rack problem, strut mount problem, or a worn suspension component such as a ball joint or tie rod end.
If the shop could find nothing obvious then I’d want it on the alignment rack to see what’s going on.
I had a Mitsu Galant that acted like that. Turned out to be spalled ball joints. With no lubrication, they simply would not turn or re-trun properly. Power steering made it turn sort of OK, but the PS would not turn it back to center.
I took it to my favorite alignment shop. When they priced the parts, they were only available as a complete unit WITH the lower control arm. When they called the DEALER they were told that my car was subject to a factory recall for this dangerous defect. NO CHARGE!! It would have been about a $600 repair otherwise.
I’ve had lots of cars that tracked straight, but needed serious alignment work. My favorite shop says that radial tires are often very forgiving of poor alignment. Get it checked out.
Radial tires may be forgiving about tracking due to alignment, but they are not forgiving as far as tire wear is concerned. A very small misalignment, even if it is at the limit of the tolerance can shorten the tires life by half or more.
But, I think the problem in this case is with a ball joint or tie rod end that is seizing. It could also be in the coupler for the steering column or remotely possible in the cradle where the steering column attaches to the dash board.
The problem is that all these things will work and may not show any slop so finding the culprit can be very hard. If you lucky, you might find it by putting the car on the lift, then when everyone is gone for lunch, or after the shops normal hours when everything is quite, engine off, turn the steering wheel and the offender might squeak. There could also be some excessive drag inside the rack and pinion.
Since your guys have looked at the articulating joints, and since you didn;t mention play in the steering, I’m going to go with the power steering contrtol valve (spool valve) not nullling out properly. It should be at the null position when the wheel’s level, but if it’s nulling out too early it’ll require manual input each time to center the wheel. This seems possible of the bearings are worn.
Caveat: I’ve never torn one apart. I’m speaking theoretically only.