Why a "high lift jack"

[Olyfboer]

Personally I never let go of the handle when down is selected. If you run out of puff keep hold of the handle. Tea breaks are reserved for the way up, when the handle can be left lying down, I would think as the handle can’t fall from that position. Last time I used my HLJ it didn’t feel like it wanted to runaway up the ladder. Personally I’m not happy leaving all that potential energy at the mercy of a wire clip. I don’t believe in leaving things in an unstable condition held by a safety pin.

Going up the ladder uses your energy input to lift the vehicle. A runaway is caused when going down the ladder and the weight of the the vehicle and gravity cause the jack to climb down the ladder, causing the handle to move rapidly. Stoppong that handle or getting in it's way will bereak something you were born with.

The safety pin used when selecting "Down" will prevent the lever falling while you select. That is all that is required to prevent a runaway

Safety and split pins are used in many engineering applications and are proven safe, as in this application:

[K-9]

"The safety pin used when selecting "Down" will prevent the lever falling while you select. That is all that is required to prevent a runaway

Safety and split pins are used in many engineering applications and are proven safe, as in this application:"

Nicely said:-

This runaway; once started is like a runaway freight train and stops only when the jack falls to one side, having lowered the vehicle completely to the ground. I saw this happen in 1988, it knocked out cold the person sitting next to the vehicle, at Savuti at about 18:30 at night. It could have been a terrible drive to the hospital, we stapled him up and his brother watched him all night. The next morning he could not remember being hit and blamed the booze for his headache. My freezer was partly to blame as I allowed people to put warm beers inside, the first cold beers they had had in weeks. (They where changing a front broken spring on a old land rover, as the vehicle started dropping he dived out from underneath, into the path of the handle.)

[JCMostert]

https://www.youtube.com/watch?v=61Hwm0ei1UM&t=56s

The power of the jack

[AardvarkNV]

https://www.youtube.com/watch?v=61Hwm0ei1UM&t=56s

The power of the jack

Mess around and find out

[BruceB]

Going up the ladder uses your energy input to lift the vehicle. A runaway is caused when going down the ladder and the weight of the the vehicle and gravity cause the jack to climb down the ladder, causing the handle to move rapidly. Stoppong that handle or getting in it's way will bereak something you were born with.

The safety pin used when selecting "Down" will prevent the lever falling while you select. That is all that is required to prevent a runaway

Safety and split pins are used in many engineering applications and are proven safe, as in this application:

Yes I’m aware of the energy input. Safety pins are quite frowned upon in most applications. Working in Oil and Gas I’m sure you’re aware of the term secondary retention.

I think you’ve missed the point of my post. In safety engineering your first course of action when identifying a risk is to remove the risk. Leaving the drive mechanism in “up” is as close to removing the risk as possible. It’s essentially impossible to have runaway. Saying you should keep the lever linked into a wire clip is an administration control. How many admin controls does the safety team allow you to get away with when messing about with the BOP? I’m guessing very little.

Hopefully that explains where I’m coming from.

[Petri Oosthuizen]

Ek weet nie hoe werk die ding nie.

Jare terug een op my Defender se bumper vasgemaak omdat dit cool lyk, maar dis die naaste wat ek aan 'n HLJ gekom het. Ek onthou net die ding het moeruit gerattle op daai bumper.

Ek hoop maar my pel voor of agter my het een as ek vassit, of daars 'n boer iewers naby met 'n ou Massey.

Nog nooit so iets nodig gehad nie, mind you. Ry nie so rof nie. Of eks maar net lucky.

[Olyfboer]

Yes I’m aware of the energy input. Safety pins are quite frowned upon in most applications. Working in Oil and Gas I’m sure you’re aware of the term secondary retention.

I think you’ve missed the point of my post. In safety engineering your first course of action when identifying a risk is to remove the risk. Leaving the drive mechanism in “up” is as close to removing the risk as possible. It’s essentially impossible to have runaway. Saying you should keep the lever linked into a wire clip is an administration control. How many admin controls does the safety team allow you to get away with when messing about with the BOP? I’m guessing very little.

Hopefully that explains where I’m coming from.

Oil and gas is a whole new ballgame with explosive pressures, poisonous gases, massive shear and torque forces, hazardous substances, heavy objects that can fall from heights, massive stored energy (The HLJ jacks itself down due to stored energy) and complex systems. All jobs also require a meeting of all personnel involved; - the "toolbox talk", their input and safety concerns. A risk assessment (JSEA), a procedure and everything signed by all involved. Doing this to jack up a vehicle would definitely help prevent an accident but would be a very lengthy exercise and rather OTT and OCD. Oil and gas industry rules would also require all involved and bystanders to wear full PPE. Imagine jacking up a vehicle wearing a full coverall with reflective strips, riggers impact gloves, steel toecap boots, hard hat (in date), safety glasses and hearing protection?

Leaving the drive mechanism in “up” is as close to removing the risk as possible. It’s essentially impossible to have runaway.

Correct. But what happens if the lever drops while you're changing the direction selector from raise to lower? That will cause a runaway and is the sole reason the safety clip is used - To prevent the lever from dropping while changing the selector. That makes it an engineering safety control, not an administration safety control as it physically prevents the lever from dropping. Your JSEA in the oil and gas industry would have regarded ensuring the safety clip was engaged noted as a critical safety procedure and to be checked by more than one person. A secondary safety such as a tywrap may have been required as well.

Reading all the arguments, I'm beginning to wonder how many people have actually used the HLJ?

[Olyfboer]

https://www.youtube.com/watch?v=61Hwm0ei1UM&t=56s

The power of the jack

And that was while jacking up when the handle can't run away. The cardinal rule when jacking up or down; - Don't get any part of the body between the handle and the jack.

[Orxy]

this is why: when you're in lion country, a bottle jack just won't cut it

[Peter Connan]

Reading all the arguments, I'm beginning to wonder how many people have actually used the HLJ?

Indeed. Looks like almost everybody is seriously scared of it.

Honestly, if used with common sense and understanding, it's far less dangerous than the vehicle it is bolted/clamped/tied to.

[bfreesani]

So I said I was done, and left, but something happened this morning that is a first for me while using a HLJ. And yes, it was my fault. Simple case of house keeping that should have been done.

My HLJ was covered in sand from the last use due to high wind blowing up the finer particles into the lightly lubricated mechanism. Half way jacking up, I find my jack acting strange. The pins are not reacting as they should at the end of each stroke. I have had this once before when things get bunged up with too much dust and sand. In this type of emergency, anything will do to clean the sand, and get some type of lube going. But now I first need to make this jack safe. It's half way doing the required lift. I have just got the handle to the top stroke, and waiting for the pins to click through so that I can get into the next down stroke. No pin movement, it's all bound up. When I go for the lever to go into the down position, it is sitting halfway between it's positions.

The handle is floppy in it's top position, and does not pick up tension when you start pushing down on it. SO where should it be in the jacking cycle Go for the safest place I know, and that's in the most upright position. All I got to clean with is some diesel (well it's mostly cooking oil, but there's about 30% diesel). The direction lever does not want to go into the down position. Get it into the up position and cycle once or twice to get some lube into the mechanism. Then I see something that I did not realise would be possible. At the bottom of my jacking stroke, the handle pushes my direction lever into the down position. I saw it just in time to make myself ready for any possible reaction from the HLJ.

After some cleaning and lube it started reacting better, and got the job done. I thought that maybe my HLJ has seen too much use in the sand, and things have worn out too much, but after a strip down and full clean, and some light lubrication, it's working perfectly again.

I don't know if anybody else has had this change of direction when the mechanism gets dirty, but this is something to be very aware of.

[Rustie]

Hierdie olyfboer outjie is erg op sy perd as jy nie saam met hom stem nie en dan hou hy aan en aan en aan soos n plaat wat vashaak.

[Olyfboer]

Hierdie olyfboer outjie is erg op se perd as jy nie saam met hom stem nie en dan hou hy aan en aan en aan soos n plaat wat vashaak.

Hoekom dra jy nie by op die onderwerp instede van die skrywer aan te val nie? Is ek reg of verkeerd? As jou antwoord nee is, verduidelik hoekom ek verkeerd is? Of is jy ook van daardie wat nog nooit 'n HLJ gebruik het nie maar baie het om te se?

En op my ouderdom, is ek glad nie jou outjie nie. Wat was dit nou weer oor verkleinwoordtjies?

[Olyfboer]

So I said I was done, and left, but something happened this morning that is a first for me while using a HLJ. And yes, it was my fault. Simple case of house keeping that should have been done.

My HLJ was covered in sand from the last use due to high wind blowing up the finer particles into the lightly lubricated mechanism. Half way jacking up, I find my jack acting strange. The pins are not reacting as they should at the end of each stroke. I have had this once before when things get bunged up with too much dust and sand. In this type of emergency, anything will do to clean the sand, and get some type of lube going. But now I first need to make this jack safe. It's half way doing the required lift. I have just got the handle to the top stroke, and waiting for the pins to click through so that I can get into the next down stroke. No pin movement, it's all bound up. When I go for the lever to go into the down position, it is sitting halfway between it's positions.

The handle is floppy in it's top position, and does not pick up tension when you start pushing down on it. SO where should it be in the jacking cycle Go for the safest place I know, and that's in the most upright position. All I got to clean with is some diesel (well it's mostly cooking oil, but there's about 30% diesel). The direction lever does not want to go into the down position. Get it into the up position and cycle once or twice to get some lube into the mechanism. Then I see something that I did not realise would be possible. At the bottom of my jacking stroke, the handle pushes my direction lever into the down position. I saw it just in time to make myself ready for any possible reaction from the HLJ.

After some cleaning and lube it started reacting better, and got the job done. I thought that maybe my HLJ has seen too much use in the sand, and things have worn out too much, but after a strip down and full clean, and some light lubrication, it's working perfectly again.

I don't know if anybody else has had this change of direction when the mechanism gets dirty, but this is something to be very aware of.

I have experienced not being able to get it to select lowering due to dirt. I could raise but not select lower. Clamped the handle in the up position and sprayed WD40. Still no select but after raising two more strokes it selected lower.

[BushNomad]

... its a time-tested piece of equipment, like a hammer etc ...
... not some new fandangled gadget ...
... so cant understand logic of giving it the hoof ...
Guys say its dangerous , yet same folk quite happy to use an angle-grinder in any situation, without goggles etc ...

[bfreesani]

I have experienced not being able to get it to select lowering due to dirt. I could raise but not select lower. Clamped the handle in the up position and sprayed WD40. Still no select but after raising two more strokes it selected lower.

Mine would select the up position, but when I reached the bottom of the stroke with the handle, it would push the selector out of position and half way down. At the time I thought it could have been fully in the down position, as I never experienced "half way". But with enough crud in the mechanism, this seems possible.

As you say, it did come right with some lube and few cycles. All I had with me was the fuel I could scavenge from my tank. But from a safety aspect, I was darn close to just pushing the car off the jack to get it out and inspect the problem without a ton sitting on it at nearly a meter high.

Lesson = KEEP IT CLEAN.

[Francois Theron]

I think one of the most fundamental points in using a HLJ is to keep the mechanism clean. Otherwise BIG trouble!

[Rustie]

I think one of the most fundamental points in using a HLJ is to keep the mechanism clean. Otherwise BIG trouble!

There is a small checklist of rules.
The top 3 rules are:
- Only I get to install and operate it, you don't touch it.
- Secure footing and "pole vault" awareness as you lift up to required height (and that can be ANY height dictated by the situ).
- Keep the mech clear. x10.

[grips]

... its a time-tested piece of equipment, like a hammer etc ...
... not some new fandangled gadget ...
... so cant understand logic of giving it the hoof ...
Guys say its dangerous , yet same folk quite happy to use an angle-grinder in any situation, without goggles etc ...

I do agree there are tools in my Work Shop that have a bigger potential to cause more serious harm than High Lift.
Been using a High Lift for many years with no harm done.

Do not go anywhere without it. Have found that when you are serious stuck and everything like winches and snatch ropes fails the High Lift is the one to rely on.

[Hedgehog]

The point of this thread was not about the jack being dangerous, it was about the relevance of it's need on a modern 4x4..