Almost everyone has changed a tire at some point in their life. While a spare tire is acknowledged as a necessity, the second most important tool for the job is a jack. Without it there is no way to lift the vehicle off the ground.
Jacks and jack stands are not just for changing a tire. They can also convert any space into an automotive workshop in no time at all, making it possible for users (and mechanics) to perform maintenance and vehicle repairs right in your own driveway.
Jacks and jack stands are extremely safe and reliable as long as they are used correctly and the correct jack and stand is used for the vehicle weight.
Jacks and jack stands explained
Jacks
A vehicle jack uses the power of hydraulics to lift up part of a car allowing the user access to change a tire or perform repairs or maintenance. Jacks come in a variety of types and weight ratings. Choosing the right kind of jack for the work being performed is key, not only for the safety of the mechanic, but the vehicle as well.
Almost every new vehicle sold comes with a jack as a standard tool for changing a tire. While these jacks are certainly up to the task of lifting the vehicle a few inches off the ground to change a tire, for more in-depth work a second jack or jack stands are required.
It is always wise to be cautious when using a jack. If the vehicle to be lifted weighs 2 tons, use a jack that is rated for at least 2.5 tons. Never use a jack on a vehicle that is over its rated capacity.
Jack Stands
Jack stands are tower or tripod shaped and are designed to support the weight of a raised vehicle. They should be placed under the vehicle axle or frame to provide additional support for an elevated car.
Once a vehicle is jacked up the stands are put in place and the vehicle is lowered onto the stands. There are saddle shaped tops on jack stands, which are designed to support the vehicle axle. Stands should only be used on hard and level surfaces and only for the vehicles that are within the weight capacity of the stands.
Jack stands are available in different types and are categorized by maximum height and weight capacity. In most cases, the height of a jack stand is expressed in inches and the weight capacity is in tons.
Jack stands are usually sold in pairs and are most commonly used with floor jacks. Stand heights typically range from 13 to 25 inches but can range all the way up to 6 feet. Weight capacity can go from 2 tons up to 25 tons.
Jack stands are mainly used for repairs or maintenance, they are not commonly used to change a tire.
Different types of jacks
Floor Jack
A floor jack is the most common type of jack used for maintenance and repairs. They are easy to move around and position in the exact spot that needs to be lifted. A floor jack consists of a low to the ground unit with four wheels and a long handle that the user pumps to operate the hydraulic lift portion of the jack. The jack saddle is a round disk that makes contact with the vehicle.
The low profile of the base unit allows it to be easily maneuvered. The handle must be turned clockwise which closes the valve before pumping the handle to raise the jack. The handle is turned counter clockwise to open the valve and lower the jack saddle.
Floor jacks are the workhorses of the jack community and they are extremely helpful when performing work that requires the mechanic to get underneath the vehicle.
Scissor Jack
A scissor jack is the type of jack that most people have in the trunk of their car. It uses a screw mechanism to produce the lifting power. The main advantage of this type of jack is its small size and portability.
The jack is placed underneath the spot to be lifted and the screw is turned using a handle to raise or lower the vehicle. In many cases the handle will be the tire iron that is included with the car.
In most cases the jack that is included with the vehicle is designed to fit the specific lifting spots on the car. If a replacement is needed, verify that it will fit the car and has a lifting capacity that is appropriate for the vehicle.
Hydraulic Bottle Jack
This bottle shaped jack uses hydraulic pressure to lift heavy vehicles and other large equipment. These jacks have a high lifting capacity and must be used on a hard and level surface. A lever is inserted and pumped to lift the vehicle.
While bottle jacks are high capacity and are quite portable, they lack the mobility of a floor jack and are not stable enough to be used on the side of a road, making them less than ideal for changing a tire.
As with all jacks, check the lifting capacity of a bottle jack against the weight of the vehicle before using it.
Hi-Lift Jack
This is a specialty jack that is used with lifted or off-road vehicles. These jacks are mainly used in off road situations or where rugged terrain limits the use of other types of jacks.
Hi-lift jacks are often high capacity, rated up to 7,000 pounds and can lift a vehicle up to five feet. They are usually 3 to 5 feet long and can weigh up to 30 pounds making them unsuitable for carrying around in a typical car.
Different types of jack stands
Stand Material
There is not a lot of variance in jack stands but the material they are made out of can make a big difference.
Small, lightweight stands tend to be made out of aluminum or light steel. Jack stands made for heavy duty vehicles should be made of cast iron or steel.
Fixed Height
These stands have a fixed height, which gives them the advantage of having zero moving parts to fail. However, they cannot be adjusted so they are not as versatile and are not really portable. These stands are extremely reliable and durable and if they are only used in one location with the same vehicle, they are a great choice.
Adjustable Height
Adjustable jack stands allow the height to be adjusted. The most common type is a tripod stand using a notched center column for the height adjustment. The height is adjusted using an attached ratchet.
Heavy-duty adjustable jack stands often use a steel pin that is inserted into holes in the center column. High quality stands will come with a second safety pin.
The final type of adjustable height jack stands are called rotation stands and the user must turn the center column clockwise to raise the height and counterclockwise to lower it.
Safety tips
Jacks and jack stands are very safe when used properly but there a few safety tips that should be followed:
Consult the owner’s manual for the recommended lift and support spots on the vehicle.
A jack should only be used to lift the vehicle off the ground. Jack stands should be used to hold it in place.
Always use jack stands if working underneath a vehicle, never go underneath a vehicle that is only held up by a jack.
Always block the wheels before jacking up a car. This will keep it from rolling. Bricks, wheel chocks or wooden wedges work well.
A jack and jack stands should only be used on a level surface.
The car should be in park and the parking brake engaged before the vehicle is jacked up.
Gently shake the vehicle when it is on the jack stands to ensure it is secure before going under the vehicle.
