Power steering: is this normal?

<div class='quotetop'>QUOTE(Katrina @ Mar 14 2007, 01:02 PM) [snapback]405553[/snapback]</div>

I went back and read your original posting. Trying to put into words how the steering feels is difficult. (BTW, I now have more sympathy for service managers who have to try to diagnose a problem based only the customer's description of the car's behaviour.)

Your symptoms sound similar to mine. In my case, as time went on, the "knock" also happened when making a 90 degree turn while accelerating.

As I mentioned, my dealer authorized the steering shaft replacement even though the technician couldn't replicate the "knock", and even though my 2006 was not among those covered by the steering TSB. It's apparent that not all dealers are so accommodating.

 

Well, 3500 kms (2100 mi) after the intermediate steering shaft was replaced, the "knock" in the steering started again.

This time, the technician reported that the "lower coupler on the steering shaft is notchy." The part has been ordered.

As I've mentioned previously, my '06 was not included in the steering shaft recall, but apparently it has the same defective parts.

 

<div class='quotetop'>QUOTE(JayGoldstein @ Apr 12 2007, 11:18 AM) [snapback]422072[/snapback]</div>

Well, the steering sliding yoke was replaced last week (@17,200 km). Unfortunately, I sometimes still can feel a slight "knock" (or momentary resistance) when turning the wheel quickly while the car is standing still or moving very slowly. If I avoid turning the wheel quickly in those situations, the steering is smooth. I've driven all kinds of cars with power steering, and the Prius is the only one that has acted this way.

I understand that the Prius' electronic power steering includes a "torque sensor." Could a problem with the torque sensor cause the symptom I've described? If someone briefly can describe what the torque sensor does, I would greatly appreciate it.

 

The "knock" is felt while turning the steering wheel 180 to 360 degrees degrees to the left or right of centre. I've never felt it when the steering is at a full lock. I've noticed that the "knock" has become especially noticeable after the car has sat over night. In that case, I can make it happen by rotating the wheel back and forth through an arc of about 45 degrees to the left and to the right of centre.

The technician who has worked on the car has determined that this is not normal. The big question is what is causing it. Since the "knock" went away (temporarily) after the intermediate steering shaft was replaced, is it possible that the replacement shaft also is defective?

The service department at my dealership views this situation as a challenge to their troubleshooting skills, so I'm optimistic that, ultimately, the solution will be found. I'm taking the car in again next week and will see what they come up with.

 

Here's an executive summary of the latest news on my steering issue.

I took the car in on May 7th @ 17,600 km. The technician initially said that the "knock" in the steering was typical of the Prii he had worked on. He invited me to compare my car with a 2007 Prius. The steering on the 2007 was very smooth. We then tried a 2004 Prius that was on the lot. It also had very smooth steering. At that point, the technician agreed that my car's steering was not like the others.

He proceeded to check for any loose steering components and reported that everything was to specification. He adjusted the alignment of the replacement intermediate steering shaft. When I tested the car afterward, the "knock" was gone.

I'm hoping that this is the end of the saga. If not, you'll read about it here.