Electric steering does have a "weird" feeling. I don't know if I call it what you did. I know this is my second vehicle with it and I don't like it. Though I do like how it simplifies under the hood. Funny too, even my Kubota tractor has electric power steering. Don't like the feel of that either though I do like being able to turn it with finger tips

 

I'm not sure what you mean by "notchy," but it took me a while to get used to the feel of my Highlander's steering, especially on the highway. I had to make constant little corrections to keep it going straight. At first I thought the steering was loose, but when I tested it by making very slight movements of the wheel, it responded. I think I finally figured out that the issue is that the steering wheel won't return to center when it is slightly off of center. I have to actually push it back to center, whereas hydraulic steering tends to go back on it's own.

I'm used to it now, and it doesn't bother me anymore.

 

You are describing it. On the highway, I make one little bump to the right, it goes right. I make one little bump to the left, it goes left. No slack but it's almost like memory steer instead of freely returning to center. It is the only car I have with electric steering. Not super excited about it.
But thank you for confirming my suspicions. Others in my circle think I am crazy particular (about cars).

 

I think there are other components that are worn out. Since you have the same issue when the steering wheel was disconnected from the intermediate steering shaft, I am thinking it may have something to do with a part in the steering wheel. Have you considered the clock spring in the steering wheel? Those do go bad and can give notchy feeling in the steering.

On the side towards the wheel, worn out ball joints can give weird loose steering feel. Replacing those gave my car a quieter ride and a tighter steering feel. Lastly up top would be the strut bearing up top holding up the strut mount. These rarely go bad but it is possible that the bearing is worn or damaged or possibly corroded. That would contribute to notchy steering feel.

 

My '08 electric steering was always artificial feeling with little to no return to center force. Nothing materially worn or defective. From a little research back in 2012/13 I believe the issue is that there is comparatively very little caster (2.6 degrees) designed into the suspension. I suspect to keep a light steering feel without the extra torque and wear/tear on the electric steering motor to fight against higher caster settings.

Manufacturing tolerances can be +/-, so with vehicles that are to closer to 2 degrees will tend to wander a bit more and have looser on-center feel, than ones closer to 3 degrees. I believe my Honda's and current Mazda have 5.5 to 6 degrees caster. The Mazda has electric steering and very good on-center and return feel.

If some creative DIY found a way to waller out the upper strut tower bolt holes to increase caster, an improvement in steering feel might be had.

 

Good info.
thank you.

 

The intermediate steering shaft was troublesome, but not the whole problem. A lot of vehicles were shipped with defective ones ( other manufacturers as well ) that made a knocking noise going over bumps. Toyota never admitted it, but would gladly install a new one ($175 part) for about an hour labor. That would tighten up the steering feeling a little. Cackeyed alignment will make any car wander side to side and never center- something to have checked. Raingrooves on the road can make certain tires wallow around. Have the steering calibration reset. That can give a better on-center.

 

Okay, I am going to put a fork in this one and call it a success.
The steering has consistently been bumpy or notchy until recently when it got more so. Became dangerous to drive. One of my drivers even had to power through a hard spot in the steering while making a corner.
For my Highlander, I ordered 45250-48161 Column Assembly upper.It is expensive. My parts guy at T said he never sells this part. It is the upper steering column with the electric motor attached. About two hours labor cost. I had someone else install it.
Success! Steering is now smooth, bumpy/notchy steering is gone. Enjoyable to drive now. Expensive repair but worth it.