Ignoramus23641 wrote:

Would it be safe to work under a jacked vehicle, if I use a mechanical
jack like this:

https://picasaweb.google.com/lh/phot...eat=directlink

NO. I dropped a car off a hydraulic jack once, and it almost landed on me.

Maybe if you chocked the wheels that are still on the ground, but you
really should use a jack stand that won't tip over.

Good Luck!
Rich