Retorquing your wheels: why 50 to 100 km matters

Lug nuts hold the wheel to the vehicle. They only do that properly at the right torque, which is the amount of twisting force the vehicle maker specifies. A shop tightens to that number when the wheel goes on. The second check is what makes sure it stays there.

Why the torque changes

In the first few kilometres, the wheel settles against the hub. The weight of the vehicle, the wheel turning, heat from the brakes and bumps in the road can all shift how the nuts are seated. Dirt, rust or sand between the surfaces can also give a false reading the first time: the wrench clicks, but the clamping force is not really there.

Doing it right

• Tighten in a star pattern on five-stud wheels and a cross pattern on four, so the wheel pulls down evenly.
• Finish with a calibrated torque wrench set to the vehicle’s specification.
• Clean the hub face and the studs first. Corrosion between the hub and the wheel is a common reason wheels work loose, no matter how often they are retorqued.

Too tight is also a problem

A stud that is over-tightened stretches. Stretch it far enough and it is permanently weaker, and more likely to crack or shear. Uneven or excessive torque can also warp brake rotors, damage the seats on alloy wheels and strip the hub.

What to do

After new tires, a changeover or any wheel work, come back between 50 and 100 km and have the lug nuts checked. It takes a few minutes. No appointment is necessary.