Sure, the vehicle's parking pawl, transmission or parking brake (or all three) should hold it stationary, but a little insurance is still a good idea. These little wedges can prevent a car or truck from rolling back when lifted, something that, as you might imagine, can cause all kinds of trouble.
Aside from jack stands, a good set of wheel chocks is recommended, too.If the floor jack drops it may not hurt you, but it could damage the vehicle, and that's never good, either. You can get away without using jack stands if you're, say, only swapping out wheels or something where you're not crawling underneath the car or truck, but even in these situations it's better to be safe than sorry.Always use jack stands, which will support the vehicle should the car jack, you know, not. If the jack fails or someone else bumps it, you could be maimed or crushed to death. Never do this, like, ever because it's super dangerous. One of the most important things to know is that you should never climb under a vehicle if it's only supported by a jack.Torin Hydraulic Ultra Low Profile Heavy Duty Steel Floor Jack Pittsburgh Tools Compact Aluminum Racking Jack Torin Hydraulic Low Profile Trolley Floor Jack Arcan Hybrid Heavy Duty Low Profile Floor Jack
