Lifting a vehicle for maintenance or a tire change requires precision to ensure safety and structural integrity. Placing a jack or stand in an unreinforced area can cause significant damage to the chassis or undercarriage components. Understanding the specific points engineered to bear the vehicle’s weight is essential before any lifting action. The correct procedure involves steps that prioritize stability and load distribution.
Essential Safety Preparation
Before positioning any lifting device, the car must be parked on a level, hard surface such as concrete. Soft ground like asphalt or gravel can compress or shift under the concentrated load, increasing the risk of the vehicle slipping. The parking brake must be engaged, and the transmission set to Park (automatic) or the lowest gear (manual). Wheel chocks, which are wedge-shaped blocks, must be placed snugly against the tires opposite the end of the car being lifted to prevent rolling motion.
Locating Manufacturer-Designated Jack Points
For routine tasks like changing a single flat tire, use the manufacturer-designated jack point nearest the wheel. These reinforced sections of the unibody structure are designed to withstand the upward force of a jack without fracturing. They are typically found along the lower edge of the vehicle, often referred to as the rocker panel or side skirt.
The designated lifting area is often marked by a pinch weld—a seam of two layers of metal—that contains small notches, arrows, or stamped triangles indicating the exact placement. These markers are usually located just behind the front wheel wells and in front of the rear wheel wells. The thin, exposed pinch weld is susceptible to bending if the jack is placed incorrectly.
To protect the metal seam and ensure a secure lift, use a jack pad adapter or a saddle with a dedicated slot that cradles the pinch weld. Utilizing the factory-specified point distributes the vehicle’s weight across the strongest part of the body structure at that corner. Consulting the vehicle’s owner’s manual provides the authoritative diagram and description for these specific lift locations.
Structural Points for Central Lifting
When raising an entire axle for maintenance, a floor jack is positioned at a central structural point. This allows both the front or both the rear wheels to be lifted simultaneously, creating space to place jack stands at the reinforced corner points afterward. The front subframe crossmember, a substantial structural beam supporting the engine or transmission, serves as the central lifting point for the front of most modern vehicles.
For the rear, the solid rear differential housing provides a robust central lift point on rear-wheel-drive vehicles. Front-wheel-drive vehicles without a differential may use a thick, structural rear axle beam. It is important to avoid placing the jack saddle on thin sheet metal, the oil pan, exhaust system components, or suspension links, as these areas are not designed to handle the load and will sustain severe damage. The large, flat saddle of the floor jack must be centered precisely on these heavy-duty components to ensure the load is balanced during the lift.
Securing the Vehicle with Jack Stands
A jack is only a lifting device and must never be used to support a vehicle while a person is working underneath it. Once the vehicle is raised, a pair of appropriately rated jack stands must be immediately positioned underneath a structural support point. The stands are engineered to hold the static load for an extended period.
The placement points for the jack stands often differ from the central lifting point to allow both devices to be used simultaneously. Acceptable locations include the frame rails on body-on-frame vehicles, or the dedicated, reinforced stand pads found adjacent to the factory pinch weld jack points on unibody cars. The vehicle is then slowly lowered onto the jack stands until the entire weight rests securely on them. A final check involves a gentle push on the vehicle to confirm stability before any work commences.