Use Jack Stands
The common metal tools known as jack stands are critical safety items for those who need to work underneath vehicles. Putting up a vehicle on jack stands correctly can be the difference between a successful maintenance/repair and a tragic accident. People using jack stands can follow some simple steps to avoid potential disaster.
Steps
- Locate a level workspace. Jacking up a vehicle on an incline or other uneven surface is extremely unsafe. Make sure your work space is level and the area under the vehicle is correctly paved and firmly supported.
- Consult your owner's manual. The owner's manual for a vehicle generally has information about safe practices for raising your vehicle off the ground.
- Find the "curb weight" for your vehicle and make sure that your jack stands are rated for that weight. It's important to have stands with an adequate safety rating for the size of your car or truck.You can find this in your owners manual, online, or on the plaque in your door jamb
- Set the vehicle's parking brake. This will prevent the vehicle from rolling while it is supported. In addition, use wheel chocks on both sides (front and rear) of the wheels opposite (front or rear) to where you are lifting to prevent the car from moving forward or backward. A car lurching forward or backward can fall off the jack and injure or even kill you. WARNING: Chocks are essential when the rear wheels are lifted since the parking brake usually sets on the rear wheels. Without a chock, the front wheels can roll even if your parking brake is on.
- Use a floor jack to lift the car. Many cars come with a standard jack (like a scissor jack) and wrench that ship with the vehicle from the factory but these are not for standard use, only for only emergency tire changes. For regular jobs, use a floor jack, a generic jack that can lift all vehicles effectively, such as a hydraulic trolley jack. Only use the jack on a solid, level surface such as concrete. Never use jack stands on soil, wet ground, or hot asphalt since the weight of the car can cause the jack stands to sink into the ground and the car can fall off them when they slip.
- Install the jack stand under a solid, structural piece of the vehicle frame. Your owner's manual will likely have information about where to support the vehicle with jack stands. Generally, your vehicle will have a small divot in the chassis near the wheel where you can put the jack stand.
- Make sure not to put the jack stand under elements like the floorboards of the vehicle. This may cause the jack to break through the floor. Also, do not put the jack stand under a moving part such as an element of the suspension of the vehicle.
- Take out the initial jack and repeat this process for the other side of the vehicle. Experts recommend using at least two jack stands of the same heights so that the vehicle is supported equally on both sides.
- Test your jack stands. When the jack stands are in place, push the vehicle with your hand to see if it moves or shakes. Make sure you push from both sides and the rear. If it shakes, reorient the jack stands (after using the jack) until the vehicle is stable.
- Add backup safety objects. Though jack stands and wheel chocks provide good stability, it is worth being extra cautious with your life on the line. For additional safety, raise the jack under a solid point under the car to the extent to where it is snug but not supporting the weight of the car (the jack stands should continue to do this). Also, you can put a spare tire (with rim) or blocks of wood under the car to catch the car if it falls. Never, ever, use concrete blocks or bricks since these can crumble under the weight of the car.
Tips
- Check out informational resources on the proper use of jack stands to prevent accidents. The National Institute for Occupational Safety and Health is one government agency that provides this kind of information to the public. Make sure you understand all of the liability associated with jacking up a vehicle before you take on projects that involve using jack stands.
- Put additional items under the vehicle to minimize risk. Some home mechanics recommend taking off the tires and placing them sideways under the vehicle. You can also use solid blocks of any sturdy material to supplement your jack stands. When it comes to working under vehicles, more safety is almost always better than less.
Warnings
- Never work under an unsupported vehicle. This is one of the most unsafe elements of mechanical work, and it should never be attempted. Using jack stands as advised will help eliminate some kinds of danger associated with auto repair.
- Always chock the wheels opposite to the car you are working on. Jack stands increase safety over an unsupported jack, but fatalities can still occur if the wheels are not blocked since the car can roll off the jack stands.
- Jack stand manufacturers provide the following warnings: Use a matched pair to support one end of a vehicle only. Use only one(1) pair per vehicle. Jack stands are not to be used to simultaneously support both ends or one side of a vehicle. Failure to heed these markings may result in personal injury and/or property damage.
Things You'll Need
- specialized vehicle jack or floor jack
- jack stands
- four wheel chocks (blocks)
Sources and Citations
- Videos provided by Engineering Explained
- http://www.techguys.ca/howto/floor_jack.html
- http://www.cdc.gov/niosh/FACE/stateface/ia/98ia071.html
- Excellent safety sheet [1]
