How to do it safely. The jack that comes with a car is for raising one corner to change a tire; never get under a car supported only by this kind of jack. To lift the car to work under it, get ramps or a hydraulic jack, a pair of safety stands, and chocks. The jack, ramps, and stands should be rated for at least your car’s total weight. Jacks or ramps must lift the car at least 8 inches for underbody work.
If all four wheels must hang free, get a hydraulic floor jack. Cheap hydraulic jacks with a screwhead are unsuitable for most cars.
Concrete is the best work floor. On anything softer, first lay down a 2- x 4foot, 1/2-inch-thick plywood sheet to spread the load. Whatever the surface, it must be level.
To drive onto ramps, turn the wheels straight, place the two ramps parallel to each other and against the tires, and have a helper guide you as you drive forward in Low or First (or backward in Reverse to raise the rear wheels). Stop when he signals; set the parking brake.
To jack the rear of a front-engine, rear-drive car, place the jack on the bulging center of the rear axle. Place a safety stand at each side, under the axle tubes or the spring mounts. To jack the front, place the jack at the center of a rectangular crossmember; position the stands under the suspension arms.
Center jacking may not be possible on a front-drive car. The owner’s manual may recommend jacking under the body side rails. If this is the case, place a jack under the rail on one side, raise the car, and put the safety stand under the control arm in front or under the coil-spring seat in the rear. Repeat at the car’s opposite side. Slowly lower the jack until the car rests on the stands. Leave the jack in place for extra protection.
If you lift a car’s drive wheels with a jack or ramps, put chocks (bricks, 4 x 4’s, or metal chocks) against the wheels remaining on the ground. If the drive wheels are on the ground, put the car’s transmission into Park or First. If the rear wheels are on the ground, also set the parking brake. Exception: on a Saab or a Subaru if you lift the front wheels, chock the rear ones; if you lift the rear wheels, put the transmission in Park or First and set the parking brake. Before jacking a car with air-spring suspension, disconnect the battery; consult the owner’s manual for instructions.