scissor jack safety

Rob2 · 03-11-2019, 03:07 PM

These AU falcons are a bugger to get up onto stands at the front, mine is anyway.
So I was thinking about scissor jacks, they are great and safe to change a wheel etc, but not if you want to work under the car on suspension etc.
Why, not strong enough or might unwind and lower the thingy ?
I have a very strong wind up model capable of supporting a couple of tonnes,
I could get another one and have two.
When they are wound up the long screw bolt protrudes out of the frame,
so if a nut was done up on that bolt back to the frame it could be wound up but not down.
A larger square plate could be welded to the base so that it will not tip.

Should be a safe cheap stand.

Your views.

**GasoLane** · 03-11-2019, 05:55 PM

NO jack is a substitute for good ramps or jack stands

stock1991 · 03-11-2019, 06:16 PM

Quote:

Originally Posted by GasoLane

NO jack is a substitute for good ramps or jack stands

and stable ground etc , if you have to ask then you not ready type of deal

**redxm** · 03-11-2019, 06:11 PM

Quote:

Originally Posted by Rob2

These AU falcons are a bugger to get up onto stands at the front, mine is anyway.
So I was thinking about scissor jacks, they are great and safe to change a wheel etc, but not if you want to work under the car on suspension etc.
Why, not strong enough or might unwind and lower the thingy ?
I have a very strong wind up model capable of supporting a couple of tonnes,
I could get another one and have two.
When they are wound up the long screw bolt protrudes out of the frame,
so if a nut was done up on that bolt back to the frame it could be wound up but not down.
A larger square plate could be welded to the base so that it will not tip.

Should be a safe cheap stand.

Your views.

Make sure your missus knows what to do with all your stuff..............

raceteam · 03-11-2019, 06:26 PM

Every single part of a jack is a potential failure point, any one of which would be catastrophic. A stand or ramp is a simple thing with less points of failure. They're also much more stable than a jack.

Rob2 · 03-11-2019, 07:03 PM

I should have explained a bit better.
If I get under it to work on steering, knuckles, rubber etc I work it up onto ramps to get under it.
But in the next few weeks I will be replacing coils and shocks with I think Kings.
I just need to get it up via the body jacking point on a stand and work beside it
not under it.
With my crook back I don't want to bugger around trying to get under it with a trolley jack under the cross member.
The rear is no problem because it is a beam axle.
I think my scissor jack with a lock nut will be okay.
My wife died in 2010.

**GasoLane** · 03-11-2019, 07:06 PM

Quote:

Originally Posted by Rob2

I should have explained a bit better.
If I get under it to work on steering, knuckles, rubber etc I work it up onto ramps to get under it.
But in the next few weeks I will be replacing coils and shocks with I think Kings.
I just need to get it up via the body jacking point on a stand and work beside it
not under it.
With my crook back I don't want to bugger around trying to get under it with a trolley jack under the cross member.
The rear is no problem because it is a beam axle.
I think my scissor jack with a lock nut will be okay.
My wife died in 2010.

I cant imagine a scissor jack unwinding, but I can imagine one collapsing.

**PG2** · 03-11-2019, 07:25 PM

Quote:

Originally Posted by Rob2

I should have explained a bit better.
If I get under it to work on steering, knuckles, rubber etc I work it up onto ramps to get under it.
But in the next few weeks I will be replacing coils and shocks with I think Kings.
I just need to get it up via the body jacking point on a stand and work beside it
not under it.
With my crook back I don't want to bugger around trying to get under it with a trolley jack under the cross member.
The rear is no problem because it is a beam axle.
I think my scissor jack with a lock nut will be okay.
My wife died in 2010.

Sorry to hear about your wife.

As others have said, do not rely on jacks to support a car while working on it.

Sliding a couple of stands under the front of it is very easy, even with a sore back. Jack it up, position the stands and let the car onto them. If your back is that sore that you can't slide a couple of stands under the car then I suggest that your back may not cope with replacing the shocks and coils.

It does not matter if you are working under or beside it, when cars fall off jacks they tend to move sideways and not simply just straight down to the floor - and Murphy's Law will dictate that it will fall towards you.

wodahs · 03-11-2019, 09:42 PM

Quote:

Originally Posted by PG2

Sorry to hear about your wife.

As others have said, do not rely on jacks to support a car while working on it.

Sliding a couple of stands under the front of it is very easy, even with a sore back. Jack it up, position the stands and let the car onto them. If your back is that sore that you can't slide a couple of stands under the car then I suggest that your back may not cope with replacing the shocks and coils.

It does not matter if you are working under or beside it, when cars fall off jacks they tend to move sideways and not simply just straight down to the floor - and Murphy's Law will dictate that it will fall towards you.

and to add to this if you have back problems you wont be squatting near the vehicle your working on but sitting , and more than likely on the ground with your legs under the vehicle
so if it does fall your not going to move in a hurry and even if you did id guarantee it all be over before you knew it was on your legs

superyob · 04-11-2019, 10:32 AM

No matter how many jacks or stands are under a vehicle, I do not allow my students to get under a car without a tyre stack under either side. Usually two Falcon size wheels, or more...

**Mechan1k** · 04-11-2019, 10:37 AM

Have seen a scissor jack bend/fold-over and collapse ..... really quickly.

I use stands all of the time just for safety sake.

BA-XT · 07-11-2019, 06:47 PM

If you read this.... or anyone else.

I have a cheap hydraulic jack from supercheap I bought in 2013... still works fine. The 1400kg one. Anyway the metal jacking plate is too small and would crush through the chassis rail.... so I use wooden off cuts and place that on the metal part of the jack, then jack the car up from the chassis rails. NOT THE SILLS where a scissor jack would go.

I do one side at a time and slide jack under.

Also handy to have a paver under tyres to give you a bit more room to work with.

Happy to post picture if it would help people and discourage them from using scissor jacks.

For the rear I jack off the suspension frame in front of the diff.

I don't think scissor jack and safety can be used in the same sentence.

.:4:. · 07-11-2019, 07:54 PM

The locknut idea isnt terrible, but still in my opinion not for getting under a car. Added safety for changing a wheel maybe. The footprint on the ground of a scissor jack is also a lot smaller. Jack stands arent too expensive. Like all safety gear dont go for the cheapest. Ive heard of failures with the ratchet style. I prefer to use my lock pin style stands getting under a car. My ramps, i cant get my bf up without munting the bumper. I could easily get the ranger up them, but i dont need to work on that. I got a cheap deal at sca for a 2500kg trolley jack and pin type stands that seem to be reasonable compared to the at the time cheap stands they also sold for $50 per pair which didnt exactly inspire confidence. You can paint a thin weld, but its still a thin weld. Yes i do have some of the cheap stands under my boat at the moment with my good ones as i need to work on the trailer axle, but 4 cheap stands and my better 2 holding up 1600kgs, i think thats pretty safe. And also, a hydraulic trolley jack will be much easier on the back pumping it up.