(See if you can guess what I got for Christmas).
When you use a trolley Jack, especially at the higher levels of lift, there is a lateral movement of the lifting head. Since we are supposed to chock the wheels, set the handbrake and put the car in gear, this lateral movement can only be taken up by the jack itself moving laterally when it is being raised. With a rough concrete garage floor and half a ton bearing down on the jack I'm a bit concerned about whether or not this will happen. Have any of you found you need to put a smooth surface underneath the jack rollers?
