Toyota Yaris 06 - Steering - kerbed enthusiasm

We've had the Yaris for about six months with no problems. Just recently, the steering has become notchy when travelling at speed for any length of time. This is most noticeable on the motorway; whilst not a lot of pressure is required to steer the car it's very disturbing to have to push the wheel against the notch as there's a sensation that the car may suddenly veer. At town speeds, and indeed up to 50 mph, the steering appears fine. I'll need to get the car booked into the garage soon but I've been advised to post on here first to canvass ideas.

Any thoughts anyone?

Toyota Yaris 06 - Steering - Peter.N.

If its got this new fangled electric steering I suspect that's where the fault lies.

Toyota Yaris 06 - Steering - kerbed enthusiasm

It does have, and that was my first assumption. However, the steering assist reduces with speed. This leads me to believe that the electric steering is probably heping to negate the problem at lower speeds. I'm hoping that it might just be some contamination in a universal joint. It's certainly better (but not fixed) since I lubricated the mechanisms I could get to from inside the car.

Toyota Yaris 06 - Steering - Peter.N.

There is usually a universal joint at the bottom of the steering column whch may be under the car, these seize up for a pastime.