ANY time you jack up a car for ANY repair beyond a roadside flat tire change, use sturdy jack stands under a solid, nonrusty frame or unibody subframe member, chock the wheels, set the e-brake, unless the repair procedure requires turning the rear wheels, and supplement the jack stands with a floor jack under a solid part of the car. BEFORE putting any part of your body under the car, rock the car while watching your jacking points to make sure they are solid. Do not get under a car if no one else is home or nearby. ALWAYS wear safety glasses or goggles when working under a car. All kinds of rust flakes, grease crumbs, sand, fuel, oil, etc. will drop into your eyes if you don't use eye protection. These safety procedures have served me well for years. THINK and take a little time to protect yourself before starting a job; it will go much more smoothly and quickly than it would otherwise, and your project will not be interrupted by a trip to the hospital or cemetery.
Take care all,