Just read this and thought I'd post as it's a reminder to all of us not to take risks. Sometimes it is annoying getting a backup jack and axle stands but accidents can and do happen.  For the extra 2 minutes hassle it might save your life.  It really isn't worth the risk.  Stay safe guys.  

http://www.dailymail.co.uk/news/article-5615471/Mechanic-21-crushed-death-jack-holding-car-collapses.html

i know a mate who experienced a simular accident while trying to remove gearbox on a vauxhall viva. jack slipped holding vehicle up and it fell trapping him underneath. fortunatley it was a light vehicle and he managed to lift car up sufficiently to crawl out. was bruised and facial injuries, but none worse thankfully. he was on his own and could have been there hours with no help. 

 unrelated,  unfortunatly he died at age of 26 from blood poisoning from a botched operation. 

1 hour ago, iantt said:

i know a mate who experienced a simular accident while trying to remove gearbox on a vauxhall viva. jack slipped holding vehicle up and it fell trapping him underneath. fortunatley it was a light vehicle and he managed to lift car up sufficiently to crawl out. was bruised and facial injuries, but none worse thankfully. he was on his own and could have been there hours with no help. 

 unrelated,  unfortunatly he died at age of 26 from blood poisoning from a botched operation. 

That's sad Ian.  Life's cruel sometimes.

Definitely best to have an extra jack to hold the car if one jack fails. My dad does this and also sometimes puts the wheel under the car if he removes it for work. You wouldn't want to imagine seeing someone crushed by a car. Would be groosum. 

No mention of axle stands being used though. Other than the fact it's obviously not as secure as using jack stands, all that stops a hyrdrualic jack from falling down and losing pressure is an o-ring. I wouldn't dare work on my car with one of those emergency scissor jacks.

I often wonder how safe axle stands actually are...  Surely it only takes one dodgy weld and a bit of use for it to fail...  Have also seen some cheap ones literally fold and collapse on a slope.  They're not safe on soft ground either, came out next morning to find my car flat on the floor with a stand on its side sunk into the sand under the gravel driveway.  

Just a few things I do now - Give the car a good shove before going under to make sure it's solid and steady.  Always make sure you've got your phone in a pocket close to hand when under the car...it's no good sat on the strut top or tool box if the car drops and no-ones around.  Keep the jack under the jacking point on one side so if it drops and someone comes to help, they can easily lift the car.  Stick the wheel(s) under the sill if they're removed.

1 hour ago, TomsFocus said:

I often wonder how safe axle stands actually are...  Surely it only takes one dodgy weld and a bit of use for it to fail...  Have also seen some cheap ones literally fold and collapse on a slope.  They're not safe on soft ground either, came out next morning to find my car flat on the floor with a stand on its side sunk into the sand under the gravel driveway.  

Just a few things I do now - Give the car a good shove before going under to make sure it's solid and steady.  Always make sure you've got your phone in a pocket close to hand when under the car...it's no good sat on the strut top or tool box if the car drops and no-ones around.  Keep the jack under the jacking point on one side so if it drops and someone comes to help, they can easily lift the car.  Stick the wheel(s) under the sill if they're removed.

Good sound advice Tom.  Also, when I use ramps (find them a little more convenient for servicing), I always place the axle stands a few mm below the sill jacking points, just in case they were ever to give way.  I also put the tyre underneath when doing brakes/calipers etc.