bumper jack
A jack designed to lift a car by its bumper.
bumper jack: the portable lever that lifts via the car's front or rear bumper
A bumper jack is a portable lifting device that uses the vehicle's bumper as its load point. Unlike a floor jack that sits beneath the chassis, a bumper jack employs mechanical advantage through a long handle and pivot to raise one corner or end of a car. The bumper itself becomes the fulcrum contact, with the jack's arm extending downward to engage under the bumper tube or reinforcement.
The mechanism typically consists of a single vertical post with a horizontal base plate that sits on the ground. A long lever arm, usually 4 to 5 feet long, connects to this post through a pivot point. As you pump the handle up and down or turn a screw mechanism, internal gearing or wedges force the post upward, transmitting lift through a hook or saddle at the top that catches under the bumper. Most bumper jacks raise vehicles 12 to 18 inches, adequate for tire changes but not frame work.
Critical limitation: bumper jacks work only on vehicles with rigid bumpers capable of supporting the concentrated load, typically 1,000 to 1,500 pounds per side. Modern cars with plastic bumper covers and thin reinforcements are poor candidates; the bumper can collapse or bend under load, rendering the jack useless or causing damage. This incompatibility with contemporary vehicle design has made bumper jacks largely obsolete for roadside work.
Bumper jacks remain useful only in specific scenarios: lightweight classic cars, trucks with solid frame-mounted bumpers, and temporary lifting on solid ground. They are lighter and more compact than floor jacks, requiring no storage space and no hydraulic fluid maintenance. However, their stability is poor compared to a floor jack; they can tip sideways if the ground is uneven or if the vehicle shifts during work.
The term reflects the jack's defining feature: it lifts exclusively through the bumper rather than the frame or axle. In older automotive trade vocabulary, these are sometimes called screw jacks when mechanical screw drives are used instead of hydraulic rams. Many technicians abandoned them by the 1990s once scissor jacks and hydraulic floor jacks became standard equipment in every vehicle.