High lift jack dangers, and how to use properly.

Hi folks, could you tell me the dangers of the hi lift type jack's when using them with a Defender. I want to understand the jack and it's limitations.

Also, what are its uses. My thoughts here are on lifting the vehicle and recovery. This is purely vehicle based and not post pulling, moving sheds etc.

Many thanks.

Mick

They can be unstable if not used on stable ground.
They can be unstable is used on stable ground and the vehicle is pushed or not chocked correctly.
The handle can bite back if not moved through its full movement. Do not put your head above the handle when moving it.

Personally I do not see a problem with them , and I have used mine to lift a vehicle.

The fact it can be pushed over can be an advantage, I have used one to lift and push a 90 sideways to get it off a tree stump the driver had managed to get it stuck on.

Lifting the vehicle to change a wheel , I would use a std bottle jack. lifting the body to allow a spring to be popped back in I would use the hi lift. Each tool has its uses.

Cheers

Dr Strangeglove said:

Hi folks, could you tell me the dangers of the hi lift type jack's when using them with a Defender. I want to understand the jack and it's limitations.

Also, what are its uses. My thoughts here are on lifting the vehicle and recovery. This is purely vehicle based and not post pulling, moving sheds etc.

Many thanks.

Mick

Click to expand...

Don't bother with one. There are much better jacks to lift your vehicle safely (almost any other jack for example) and much better ways of recovery (another vehicle for example). Just youtube hi-lift jack gone wrong and you'll see how dangerous they can be.

They are great for evetything other than jacking vehicles up.

Ronny Dahl, a well known overlander in Aus, does not like them. Check out his many videos on how to equip your vehicle and travels in Aus

I have one in the defender. So far it’s been used to tension stock fence and pull up old tree stumps, brilliant bit of kit

I used one to jack a heavy American car to service the brakes.- its was in the US and it was all there was. Horrible as it let the whole car fall over. I'm sure they are great for fences, tractors etc but as said above, not for car jacking.

Ok, from what I can see so far, the issue is the high risk of a dangerous occurance when using them. I agree, with anything high risk, eliminate the risk or find an alternative.

So first off can I identify the risks being raised;

No 1 - Full control needs to be maintained of the jacking handle. This is due to the fact that the lifted vehicle is capable of transferring the energy of the lifted truck into the jacking handle where it arcs upwards very fast and with a lot of force and this has proven to be enough to cause significant injury if someone's head is within that arc.

No 2 - if the handle is not controlled, the jack can lower the vehicle whilst whipping the handle up and down with force. Two dangers here - the whipping handle and the uncontrolled lowering of the truck.

No 3 - when lowering, after the weight on the jack is reduced enough, the jacking mechanism falls. This should not be too much of an issue but you have to be ready for it and don't have any body part under it!!

No 4- Whilst the jack is a high lift, the point of contact with the vehicle for lifting is much higher than when using other jack's but also the lifting point is on the perimeter. From what I can see this is a big issue. The jack has relatively small contact points with the vehicle and the ground. On the vehicle this can slip and pivot, and on the ground it can do a similar thing. This issue is exaggerated due to the vehicle body having to be lifted far in excess of what would be required compared to lifting from under the axle (when being used to change a wheel) As the vehicle is raised, the jack also starts to push the vehicle slightly one way which can catch you out when the tyres lose contact with the ground.

No 5 - the point of no return! When using all jack's changing from lifting to lowering is not quick. As such as jack/vehicle starts to become unstable it is not easy to recover from this situation quickly enough to stop what is happening. Due to the hi lift raising the vehicle body far higher than when you would when lifting at the axle the potential consequences are greater.

I have very little experience with a high lift so please correct and add to what I have written.

Also, just to note that I have a standard 2t trolley jack and the land rover bottle jack out of a 1991 range rover. My jack of choice is the bottle jack and I would not consider the high lift in normal circumstances - I just want to understand the high lift!

I found this quite interesting:


A high lift will do anything a winch/tirfor/bottle/trolley jack can do but won't be easier, safer or quicker... if you can get it to fit!

Dr Strangeglove said:

Also, just to note that I have a standard 2t trolley jack and the land rover bottle jack out of a 1991 range rover. My jack of choice is the bottle jack and I would not consider the high lift in normal circumstances - I just want to understand the high lift!

Click to expand...

Apart from a quick play with it when I first got my '86 RRC I've never used the bottle jack that came with it & is standard for my MY.
Simply don't trust it.
I carry one of the small Machine Mart trolley jacks & a small axle stand which takes up little space. Never had a stability issue with it.

They are unstable but very useful, so i was thinking of making something like this to help stabilize it.

That's just adding a dangerous thing to an unstable thing.
I always carry a bottle jack and jack as close to the wheel as possible. I've always found bottle jacks very safe, they never drop suddenly but i would only ever go under a vehicle with an axle stand or if out and about, the spare wheel beside me.

I have an idea about using the jack, but until I have some plans for it that I can show with drawings arc I won't go further, other than to say it will involve a twin jack adapter. I have cut some parts to make one up and when it is together I will put a photo up.

I do understand the instabilities of the hi lift, but this idea would take that out and I would not really use it in a recovery situation - unless it proves itself!!

High-lift jacks are unstable in every direction, they will allow a vehicle to slip from side to side and forwards and backwards. When they do this, the top part of the jack can be pulled into the bodywork, lights, radiator etc.
They have their uses for off road recovery, but are still bl00dy dangerous in that environment.
High-lifts are a pain to store in a vehicle, and are heavy lumps to have sliding around if not tied down.
If you want to modify anything, modify a bottle jack, find a way of making the pad at the top engage with the axle in the way an axle stand does and get give the base a bigger foot print on soft ground. It will be a lot easier to use and you will probably live longer.

I just bought a 5t telescopic bottle jack for peanuts, it goes from not very tall to very very tall using a telescopic motion and is incredibly stable.
It is bright red so you can find it if your eyes are bad.
Hope this helps...