Whats wrong ?

[Gafferbill]

This picture was posted on another caravan forum under a topic giving advice on how to jack up a caravan.
No one as yet has commented on the picture on that forum.
Has anyone any comments on this superior forum........

 

[emmerson]

I'd like to see the jack on something more firm. Even a paving slab would be better than gravel.

 

[Sproket]

Apart from what emmo has just said,

What is the far left front steady doing in fresh air & the other one just clear of the ground hmy:

So it could be just balancing on the far left wheel & jockey wheel ?

All you need is a gust of wind to create a problem

 

[Dustydog]

Bill
The jack is not located under an Al-Ko recognised jacking point.

The jack is 90 degs out of position. So as it is elevated the jack may topple over.

See my previous posts . A trolley jack used anywhere other than under the actual axle tube and in the correct lineage is a disaster waiting to happen.

Use a bottle jack or the scissor jack recommended by Sproket under the correct chassis stiffener jacking brackets provided by Al-Ko or preferably Purple Line

 

[Sproket]

Dusty,

It is jacked up directly underneath the steel plates that secure the axle tube to the main side members, that is ok to do, but my concerns are the steadies not down to the floor, and if the back ones are clear as well it's an accident waiting to happen, ideally it should be coupled to a car or a ground mounted post to stop it moving before jacking it up ..

 

[JTQ]

Definitely the jack planted in gravel so on lifting it hauls the whole van bodily backwards rather than rolls on a hard surface as it is designed to function.
Plus the hitch is not coupled to a towcar for security, the ideal arrangement.
Plus the far side steady will be taking addition loading, far greater than its designed steadying function.
Jockey wheel would be better at 90 degrees an chocked.

 

[Damian]

Apart from the jack being on gravel which is not ideal, but workable, the jack is in one of the best positions, under the reinforced area of the axle tube fixing.

If the owner has adjusted the opposite steadies to compensate for the slight downward movement then no problem there as steadies and their fixing points are designed to take 25% of the van weight, but most of the weight will be on the opposite wheel.

From the looks of where the van is it appears to be reasonably well sheltered and would present no exceptional danger.

In all the time I have been servicing vans I have never hitched the van to a vehicle and have jacked in much worse situations than that one and never lost a van off the jack, and never had one swivel whilst on the jack

 

[Mel]

I have no knowledge of jacks but it strikes me that the photographer was lying under a semi jacked up van to take the picture.
Mel

 

[Gabsgrandad]

A trolley jack has to be capable of moving to follow the arc of the lift. Otherwise it puts 'bending moments' into the lifting point. That's why they are called "trolley" jacks and have wheels.

 

[colin-yorkshire]

This picture was posted on another caravan forum under a topic giving advice on how to jack up a caravan.
No one as yet has commented on the picture on that forum.
Has anyone any comments on this superior forum........

that axle needs a wire brush on it and a coat of paint

 

[MichaelE]

The last time i jacked a caravan up whilst it was still attached to the car we were jacking the car up as well as the van.When we released the hitch the car dropped a good 3-4 inches, wouldnt do again as surely putting extra stress and load on the jack?

 

[ProfJohnL]

The tyres not right, it should be flat at the bottom :huh:

Its already been pointed out the jack is not on a hard surface, I'm sceptical about using set paving slabs as they are often supported on blobs of cement and that can mean the slab is acting as a bridge, and under the point loads of the steel wheels I have seen slabs crack. A paving slab laid flat on the ground is better, or use a piece of plywood to spread the load more evenly.

The jack has been applied to the strongest point on the chassis where the axle bracket more than doubles the thickness of the chassis side member material, and after all when the caravan is is in motion the full weight plus the load created by the accelerated mass loading when travelling over bumps will be applied to this area of the chassis, so it is more than adequate to carry the static load of the caravan.

The direction of the jack is in my view actually better as the nearside wheel is (I assume) still in contact with the ground and will provide an effective brake to stop the jack from rolling over sideways or slip off the jack. Whilst Gabsgrandad is correct about the lifting arc, in this case it will simply apply a slight swing to the hitch as its lifted.

 

[ProfJohnL]

The last time i jacked a caravan up whilst it was still attached to the car we were jacking the car up as well as the van.When we released the hitch the car dropped a good 3-4 inches, wouldnt do again as surely putting extra stress and load on the jack?

That will depend on what part of the caravan you were jacking.

 

[MichaelE]

The last time i jacked a caravan up whilst it was still attached to the car we were jacking the car up as well as the van.When we released the hitch the car dropped a good 3-4 inches, wouldnt do again as surely putting extra stress and load on the jack?

That will depend on what part of the caravan you were jacking.

Used the Alko jacking points behind the wheel

 

[Sproket]

When you jack the van up while coupled to the car ...... you can drop the jockey wheel to stop the extra load being put onto the towball .... just remember to lift it back up before driving off ..

 

[MichaelE]

I presume you mean put the jockey wheel down after you have lifted the van?
You are still trying to lift the car up when connected to the van?

 

[Damian]

Quote " you can drop the jockey wheel to stop the extra load being put onto the towball "

Not a good idea if you put the jockey wheel down before lifting the van as you place strain which the jockey wheel fixings are not meant to take, and strain on one side of the A frame which it is not designed to take.
If you put it down after lifting, you have lifted the car as well, so no point.

 

[NigelHutson]

To put the record straight, most of the issues raised by the "publishing" of just one photograph on this forum are dealt with in the article proper. After taking advice from Al-Ko, three photographs showing where various jacks/axle stands should be placed were taken and published.

Whilst the trolley jack looks like it's supporting the caravan, in actual fact it was supported by an Al-Ko side-lift jack, and the trolley jack was put there for photographic purposes only. With regards to being on gravel, yes it is, but, it is very shallow and solid underneath (the joys of working within the confines of where the caravan is stored). On that note, it is very well sheltered, and even in gale force winds has never moved a jot!

Finally, if the article is read, you'll see that all points regarding corner steadies, being left hitched to the car etc., etc., are covered. At least it gives us pensioners something to pass the time though! :silly:

This will be my one and only post on this topic, but I hope that many fears have been allayed.

 

[Gabsgrandad]

On the subject of weight on jockey wheel, to prolong the integrity of wheel and bearings (particularly pneumatic tyre) I lift on the heel of the wheel. (Even when normal parked up.) as I find the tyre pressure 'lasts' far longer than when the weight is on the tyre

 

[Gafferbill]

The picture whether staged or not shows the incorrect use of a trolley jack.

Every trolley jack sold in the UK is done so with the warning instruction that the jack must be used on a hard level surface capable of supporting the weight of the vehicle.
This is because this type of jack is designed for workshop use on such floors as concrete.
It is essential that the body of a trolly jack can move forward on its wheels during the lift and backwards during the drop.
The lifting force, which is considerable is applied in an arc and if the body of the jack is prevented from moving, that force will cause the lifting point of the jack to move relative to the vehicle with likely dangerous consequences.

IMO a jack that provides a straight lift is much safer for caravan use by a DIY caravanner.

Well done to those that pointed out what was wrong

 

[Gafferbill]

Nigel..........my reasons for starting this topic were purely to highlight a danger in the use of trolley jacks on uneven soft surfaces.
The facts are that trolley jacks were designed for use in a workshop situation where they are a superb tool and invariably operate on a hard concrete surface.
In recent years their design has been copied and miniaturised by our far eastern friends and the price become comparable with other designs of jack.
I have noticed over a number of years that they have become very popular with caravanners and are often carried in the tow car.
I have also notice their use on completely unsuitable surfaces whilst on a campsite.
On reading through the posts to this topic you will find (completely unprompted) that Gabsgrandad and JTQ exactly pinpointed the specific dangers that I was trying to highlight.
Those dangers are that a trolley jack must be on a hard level surface so that it can move on its wheels and compensate for the arc lifting and dropping forces.
On these smaller trolley jacks it is the front wheels that take most of the weight and there is a 'stiletto heel effect' on any soft material the jack is placed further inhibiting the movement of the wheels.
If the movement of the wheels is restricted the considerable force will either move the vehicle being lifted or disturb the jacking point position with obvious dangers.

When as the OP, I posted the photograph, I did not know it was taken from a publish article as I just copied it from another forum that was discussing how to safely jack up a caravan.

You are right I am just an OAP with nothing better to do than post stuff on forums but I have a concern for the safety of others.
I would have thought that this topic would make a good article to flag up these dangers to a wider audience in the Practical Caravan magazine to which you are a contributor.

For the record..............for both my caravan and tow car when away from home I use an old fashioned screw type jack that was provided with my tow car when new.
Last used January 28th this year on the hard shoulder of a French motorway to change the front wheel of my tow car ..........stoppage time 20 minutes.
I have a hydraulic bottle and a trolley jack for garage use at home on concrete.

 

[NigelHutson]

Bill,

It's unfortunate that that particular photograph was chosen for publication, although I know that it would have been done with the best of intentions. As I said in my previous post, the caravan had been lifted by use of Al-Ko's side-lift jack, and was then put onto axle stands. That photograph (and several others) were taken to indicate the correct place for the jack to be lifting the caravan (i.e. under the reinforced plate under the axle). I must admit that I have learned something, so thank you for that.

As regards solid (and level ground), there is a concrete base underneath those chippings, which unfortunately doesn't show. In Utopia, the trolley jack should be used at 90 degrees, but as I'm sure you're aware, that is impossible on a caravan as the wheel is in the way. They're certainly used in caravan workshops (granted, on a flat floor), and probably just as regularly by the AA et al at the roadside, where things aren't so level.

As the article says (in the words of Al-Ko), the first choice is one of their jacks (or ones that use the same type of jacking point mounted to the correct places on the chassis), then axle stands, and as last resort, any other kind of jack (trolley, scissor or bottle). They are their words, not mine.

Similarly, the other points raised (such as lowering the steadies etc) were all covered in the article.

I will send in an "addendum" to PC Towers, as you suggest, recommending where and when trolley jacks should be used.

Now, I'm off to find my pipe and slippers!

 

[NigelHutson]

Bill,

After having a good session with my pipe and slippers, I have made representations to PC, and they are indeed going to amend the information regarding the use of trolley jacks in relation to caravans. I must admit that I have over the years used a trolley jack to lift the caravan without incident, and have certainly seen them used frequently in workshops at angles certainly not even near to ninety degrees. But, whilst in isolation my use of a trolley jack has perhaps not been totally correct, I have always ensured that the caravan is stable and that the jack is not anywhere near the point of toppling over. As a previous post has suggested, they have worked in worse condition/positions that the one being questioned here. However, as you say, ideally trolley jacks should be used on solid surfaces, and as near to ninety degrees as possible, and certainly not on soft surfaces (like caravan site grass pitches!).

Thanks for pointing things out (irrespective of the fact that the jack in the photograph wasn't in this case actually supporting the caravan), and I hope that when published, you find the corrections satisfactory.

Happy 'vanning!

Nigel

 

[Gafferbill]

Top notch reply Nigel......Thank you.