Can anyone explain this: I hit a pothole while making a left hand turn. Suddenly, the steering wheel was ~25 degrees from center. And it became overly responsive to any slight change in the steering wheel position. It felt fine alignment wise, but the steering wheel was suddenly angled. I hit a pothole while making a right hand turn. Suddenly, the steering wheel centered. And it responded normally to steering. I suspect the electric power steering motor is at fault, but how does a pothole cause the steering wheel position to change without the wheels changing position?
Do you mean you're driving straight ahead down the road with the wheel centered, and then you have one of these pothole incidents, and after that you're driving straight ahead down the road with the wheel not centered? The assist motor can't do that. It's only an assist. It contributes its bit of torque for you at a gear that's solidly part of the steering shaft, but it has no way to change the relative position of the steering shaft to the wheels. If you have a situation where some potholes can shift around the relationship between drives-straight-ahead and wheel-centered, you've got some joint loose enough in the front suspension or steering linkage for the potholes to flop it around, and no, you don't want it like that. I would think any decent alignment shoppe ought to be able to spot it in short order. I would not delay very much in having it looked at ... what's floppy today could get flat-out disconnected by some future pothole, and that kind of auto-pilot mod you probably don't want. -Chap
Chap - Correct! The pothole causes the relation of the steering wheel to the wheels to change. But the wheels do not change relative to each other. The wheels, tie rods, and rack all move as one and remain in the same position. The steering wheel, linkage and steering gear input shaft all move as one and occasionally changes position, relative to the wheels, tie rods and rack. Is this indicative of a loosened pinion shaft attachment nuts? Or, is it indicative of a worn pinion shaft?
I confirmed it to be at least a front lower ball joint that failed; It doesn't have any vertical play, but it does move side to side under loading. But when replacing it, I stripped the nuts and bolts, when the nuts malformed while trying to tighten to 105 ft-lbs as the manual indicates in the Service Specs and Suspension sections. I got a replacement of a different brand, and had the same results. Now, I see on DS-2 in the Drive Shaft section, the proper torque is noted as 66 ft-lbs. So, I'll be posting a new topic to clarify this, and to make it easier to find in search results in the future, should anyone have the same problem. I'll keep updating after I get another replacment in there.
I'm glad it turned out to be that, because what you were hypothesizing about shiftability between the rack and the steering shaft was not, I think, a thing that can happen. Even a slight sideways motion of a ball joint can (case in point!) make a pretty noticeable change in the direction the car goes. -Chap
