When I try to stop, my steering wheel shakes 

Hello Paul, when I drive my Toyota Premio at speeds in excess of 60km/hr and I press the brake with the intention of slowing down or maybe coming to a stop, the vehicle, especially the steering wheel, shakes so vigorously. What could be the problem? Rodney

Hello Rodney, the steering judder or shaking may be caused by one of the following two factors: unevenly worn out brake discs or rotors and extremely worn out or loose suspension and steering linkage components. Brake disc rotors wear out due to age or the use of cheap counterfeit brake pads, which are made of poor quality materials that damage the disc as you drive along. 

Uneven damage of the disc rotor surface due to intermittent thinning or warping around the rotor surface can cause juddering of brake pads when you apply the brakes at speeds of 50 kph or more.
The effect of this judder maybe transmitted from the brake discs to the steering through the steering linkage or rack assembly. 

Get a good mechanic to inspect the condition of your brake disc rotors and confirm which ones may be the culprits. Front suspension components such as ball joints, suspension plate bushes and upper control arms help to harness the wheel hub and axle to the car frame. When you brake a fast moving car, the dynamic forces will not be dampened by the damaged suspension parts. 

This may result in violent vibrations, which may feel like a judder transmitted to the steering. The mechanic should inspect your front suspension components to confirm they are all intact.