Jack stands support a vehicle only when placed on firm, level ground at the manufacturer-designated points and verified with a stability check.
Using jack stands properly is the difference between a routine oil change and a trip to the emergency room. A floor jack lifts the vehicle, but it’s the jack stands that keep it there. The correct procedure covers positioning, weight ratings, and a few safety checks most people skip.
How Do Jack Stands Work?
Jack stands are load-rated supports that hold a vehicle steady after the jack has lifted it, transferring weight from the hydraulic jack to a stable, rigid base. The stand’s saddle cradles the frame or designated support point, and a pin or ratchet locks the height in place.
Before lifting, inspect both the jack and stands for cracks, bent frames, or worn pins. Verify the stand’s load rating exceeds the portion of the vehicle’s weight it will support. The final step — a firm push against the vehicle — takes two seconds and prevents catastrophic failure.
Step-by-Step: How to Use Jack Stands
The sequence below follows manufacturer guidance and standard shop practice. Skip none of it.
Step 1: Park, chock, and brace. Park on a hard, level surface. Soft dirt, gravel, or asphalt can sink under the stands. Set the parking brake and place wheel chocks behind the wheels that stay on the ground (chock the rear wheels if lifting the front).
Step 2: Position the jack. Consult your owner’s manual for designated front and rear lifting points — reinforced areas of the frame or subframe. Place the jack saddle squarely under the lifting point.
Step 3: Lift the vehicle. Raise it until the tire clears the ground by an inch or two, giving room to slide the stand underneath.
Step 4: Set the stands. Position a stand under each side of the same axle — never use a single stand unless supporting a wheel for a quick flat repair. Place the saddle under the manufacturer-designated support point or reinforced frame area. The OTC Tools manual emphasizes locating stands at reinforced support points, not random frame spots.
Step 5: Lower onto the stands. Slowly lower the jack until the vehicle’s full weight rests on the stands. You’ll hear the suspension settle. Give the vehicle a firm shake at the bumper; if it moves or wobbles, raise it and reposition.
Step 6: Leave the jack in place. Lower it so it still touches the vehicle but carries little or no weight, acting as backup if a stand fails.
Before sliding underneath, push the vehicle hard from the side. If nothing shifts, the setup is stable; if it moves, start over.
Common Mistakes & What Could Go Wrong
Most jack stand failures trace back to four errors: soft ground, wrong placement, mismatched ratings, and skipping the stability check. Working on sloped ground or using the jack alone as support ends badly.
Positioning matters more than most realize. Placing a stand under thin sheet metal or an unapproved spot can punch through the floor pan. Also, never mix stand capacities — two 3-ton stands on one axle and two 2-ton stands on the other creates an unstable platform.
| Mistake | Why It’s Dangerous | Correct Practice |
|---|---|---|
| Soft or sloped ground | Stands sink or slide, dropping the vehicle | Use hard, level concrete or compacted gravel |
| Jack alone as support | Hydraulic seals can fail without warning | Always rest the vehicle on stands |
| Stand under sheet metal | Metal punches through, vehicle falls | Use reinforced frame points or pinch welds |
| Mismatched capacities | One side fails under load | Use matching stands rated above the axle load |
| Skipping the shake test | Unstable setup goes unnoticed | Push the vehicle firmly before going underneath |
One more rule from the OTC manual: use stands in pairs, and for full-vehicle support, use a minimum of four stands — one at each corner. A single stand at one end leaves the other on the jack, which is not stable.
Final Checklist Before You Go Under
Run through these four checks every time, no exceptions:
- Ground: hard, level, and dry — no soft soil or fresh asphalt
- Stand placement: both stands at the same height, under reinforced support points, saddle centered under the load
- Parking brake + chocks: brake set, wheels chocked on the opposite axle
- Stability test: vehicle pushed firmly — no rocking, shifting, or settling
If you’re working on a truck and need the right equipment, our roundup of the best jack stands for trucks covers rated options that handle heavy-duty loads.
FAQs
Can I use jack stands on asphalt?
Asphalt softens in heat and can sink under concentrated loads, making the setup unstable. Use concrete or compacted gravel. If asphalt is the only option, place wide steel plates under the stand feet to spread the load.
Where exactly do jack stands go on a car?
The stands go at manufacturer-designated support points, usually reinforced frame rails, subframe mounts, or pinch welds, as marked in your owner’s manual. Use matching stands at the same height, one per side of the axle, with the saddle centered under the reinforced area.
Is it safe to work under a car supported only by a hydraulic jack?
No. Hydraulic seals can bleed down or fail without warning, dropping the car. A jack is for lifting, not supporting. Jack stands are load-rated mechanical supports that hold the vehicle’s weight securely, with the jack left in place as a backup. Never trust a jack alone.
References & Sources
- OTC Tools. “JACK STAND INSTRUCTIONS.” Manufacturer manual covering placement rules, load ratings, and support points.
- CDC/NIOSH. “Be an Ace with Jacks.” Safety handout on proper jack and stand usage.