10 Steps to Jack Up a Car

Automotive experts, who are not always in agreement on how to deal with car and driving emergencies, agree unanimously on one point: never work under a car when it's raised off the ground on a jack. A jacked-up car is intrinsically unstable. For one thing, a car is meant to rest solidly on four wheels. For another, jacks can slip out from under a car for all manner of reasons. And car jacks do fail occasionally.

Just as there is a right way to change a tire in an emergency, there's a right and safe way to jack up a car to change a tire or to make any other repair that requires jacking.

What To Do

1 - Find a level place for jacking. This may mean driving a short distance on a flat tire. On a hill or slope, park across the incline, never in the direction of the slope.

2 - Put the transmission in Park or shift into a gear. Firmly set the parking brake. Turn off the engine. Switch on your four-way hazard flashers to warn traffic that you have pulled to the road's shoulder. If you have warning reflectors or, at night, flares, put them out.

3 - Before getting out the jack, consult your owner's manual for the location of your car's jacking points, the reinforced areas or fixtures under the chassis, often part of or supported by the strongest part of the car's frame near each wheel. The jacking point is designed to firmly support, engage, and fit whatever type of head (top) your jack has.

4 - Follow any special jacking instructions for your car. If your car is equipped with air suspension or another type of special suspension, you must deactivate the suspension before jacking a wheel.

5 - Inspect the areas where you'll be placing the jack and its base. Is it sandy, snowy, icy, or muddy? For safe and proper jack support you may either have to remove the sand and snow from where you intend to place the jack or prepare the jacking area in some other way. One way is to find a stout board to place under the jack. Lacking that, use the car's floor mat or trunk mat or even an article of clothing that will give the jack firm support.

6 - Even with the parking brake on and the transmission in Park or in gear, the car might still roll when one of its wheels is jacked off the ground. To prevent this, put a chock, a large rock, a large piece of wood, a cement block, under the opposite wheel diagonally from the one you intend to jack. When lifting a rear wheel and the car is on a slope, it is wiser to put chocks under both front wheels. Or you can chock all four tires. (Place chocks firmly under the tire treads in the direction the tire would roll.)

7 - Get out the jack and jacking tools. Scissor-type jacks are raised and lowered by rotating the jack handle (or you can sometimes use a wheel wrench as a jack handle). With each rotation, the jack's head will go up (or down) a little.

8 - When you are ready to jack up the car, raise the jack until its head firmly engages its jacking point. You may need to slightly lower and raise the jack several times, each time adjusting the jack or its base until the jack seems securely placed beneath its jacking point.

9. When changing a tire, loosen all the wheel's nuts while the tire is still on the ground. Even when you do jack up the car, the tire should be only two to three inches off the ground.
The higher a car is jacked and the higher a jack is raised, the more unstable both become. One reason many carmakers have abandoned bumper jacks is that even when the bumper is strong enough to be jacked, the jack must often be raised so high to get a wheel off the ground that the jack becomes unstable. The risk is that either the jack will slip, or the car will slip off the jack. That can be exceedingly dangerous to anyone changing a tire.

10. Lower the jack the same way you raised it, either by pumping or rotating its handle.