Wheel jacking weights on Motorhomes

[Stevef]

Hi;

 

Any body out there, who is mathamatically minded.

 

Problem: I have a two ton hydralic jack to be used in the event of having to change a tire on my 3.5 ton motorhome. I am told that I should not use this as it is underrated for the size of my motorhome.

My response has been that I do not wish to lift the whole 3.5 ton motorhome off the ground only one wheel(corner).

I also appreciate that when jacking one wheel you also start to lift the cross member of the chassis of the opposite wheel and to some extent the other two wheels.

 

My question therefore is jacking up one wheel to replace the wheel, how much jacking power would I need. Is it 3.5 tons divided by 4 and add a bit?

Thanks

 

[Brian Kirby]

You have not said who gave you this advice, or why, but it would be wise to check the maximum permissible rear (likely to be heaviest) axle load on your van.  I would suspect this will be 2 Tonnes +/- say 250Kg.  A two tonne jack could, therefore, under certain circumstances, be near, or at, its maximum permissible load, so a greater capacity would seem wise.

[Stevef]

Hi

It was my local tyre centre who was objecting to fitting new tyres to my motorhome as he only had 2 ton load jacks. Hhis parent company insisted he fit the new tyres but he was not happy. I had paid in advance.

[Guest Tracker]

The trolley jacks that most tyre fitters use are of much greater capacity than two tons and whilst I don't know their capacity I have often seen large trucks up on these jacks.

 

For any tyre fitter to only have two ton jacks raises suspicions to me regarding his competence and suitability to do the job properly and safely?

 

I regularly use my own two ton trolley jack to lift one wheel at a time on the van but it can still be an issue getting the darned thing to a suitable jacking point - and this may be next to impossible with a flat tyre - particularly on today's crop of very low slung vans.

[tonyishuk]

It may pay to think where you are going to jack from ?

 

If on the chassis, a real pain, because the wheel weight on the suspension will make the suspension drop and you have to jack a lot higher.

 

Or on the wheel / axle / stub where you jack the wheel clear of the ground but find that the suspension is compressed maybe beyond its load limit if the M/home is fully loaded.

 

Proabably not too much of a problem on a car, but on nearly a ton a corner (give or take a bit) on a M/home, not a place to be if the jack slips.

 

Rgds

 

 

[rolandrat]

through experience you are better off using a good commercial vehicle bottle jack up to 8 ton capacity, they never fail. Those 2 & 1/2 ton trolley jacks are a waste of time for 3 & 1/2 ton motorhomes and they can take up valuable storage space as well.

[Guest Tracker]

You can generally jack the front under the suspension and still get the wheel off but you generally, on a coachbuilt anyway, have to jack on the chassis to get the wheel to drop far enough out of its semi enclosed wheel arch to be able to remove it and therein lies the conundrum. The trolley jacks don't usually have enough range of lift to do this and the bottle jacks can be too tall to go under the chassis with a slat tyre and can also be unstable with a large motorhome at full height.

 

Best call the RAC!

[Stevef]

Thank you all for your input.

Perhaps its best I dont get involved with self changing tyres and call out a van specialist, however, if I'm out in a deserted remote location, I'll just have to try.

 

Thanks again for your thoughts

[bob b]

I carry a Draper 3 tonne inflatable airbag in the motorhome. Inflated size is 480mm x 545mm, inflating time is 50 seconds at tickover. I also have a couple of substantial rubber mats to protect the top and bottom of the airbag from damage.

Although I haven't used it in 'anger' yet, I used similar equipment in the Fire Service many times. Also it would be handy if bogged down and the motorhome needs to be raised to place material under the wheels for traction.

It is light and comes in a small carry case, so doesn't take up much room.

I should add, the airbag is coupled to the exhaust pipe and has a non-return valve, so the airbag can be dis-connected when inflated. 

[Derek Uzzell]

I've always managed to change wheels on my two Transit-based coachbuilt motorhomes (a 1996-built Herald on a Mk 5 Transit chassis and my present Mk 6-chassis Hobby) using the original Ford-supplied jack. Swapping front wheels was/is easy: swapping rears was/is far from so.

 

Anyone anticipating DIY changing wheels in an emergency situation (whatever jack(s) or jacking technique you plan to use) would be well advised to do a 'dry run' at home where there's no pressure and you can take your time. It's likely to be an educating experience, but at least you'll then know what you'll be coming up against if you have to do it in anger.

 

In my own case, the Herald's rear wheels could (just) be replaced using a peculiar muscle-wrenching ploy to get the wheel over the brake drum. With the Hobby, a dry run revealed that the spare-wheel could not be lowered/raised until I had bodged-up a tool to allow me to wind it down/up, while the rear-wheel jacking-point defined in the Ford handbook could not be utilised as the vehicle's chassis, in motorhome format, had a revised design of rear spring.

 

Having foreknowledge of the challenges involved in changing the Hobby's rear wheels allowed me to take some sort of remedial action when both of the motorhome's rear tyre-valves failed - otherwise the vehicle would have sat on flat rear tyres for two days until the valves could be replaced.

[chas]

For those who carry wheel ramps for leveling the van, one of these can be used to drive the flat tyre up onto which can give useful hieght to access to the spare wheel if the flat is on the back and allow the jack to be put into position if there was not enough room otherwise.

[Basil]

The only time I have had to change a wheel 'in anger', after a blow out on the hard shoulder of the M20, I used the standard Peugeot Boxer scissor jack without any problems at all, it fitted under the chassis with a completely deflated tyre and easily lifted to a suitable height to change the wheel.

Surely if that is what is supplied it must/ should have been tested for suitability. I do not see what the problem is with using the standard jack why waste what weight capacity you have on additional equipment that is not required.

 

Bas

[Freewheeler]

Hi Bob b,

 

I was interested in your posting because I also bought one of these Draper inflatable jacks.

 

I haven't spent much time trying it out yet, but had difficulty attaching it to my exhaust pipe because the hose supplied wasn't of a large enough diameter, so I had to improvise.

It seemed o.k. for the rear wheels, but I experienced difficulty with the air bag fouling the plastic surrounds for the front wheels.

I'll have to have another go 'cos it would be fine if it can be used instead of carrying the standard vehicle jack, being a bit lighter in weight.

 

Freewheeler.

[bob b]

Hi Freewheeler,

                      With regard to the exhaust coupling, Draper do a larger 90mm fitting.....£7.70 in 2006.

As I said, I haven't used it on the motorhome yet, but tried it on the car successfully. I would certainly chock the wheels, as they can be 'unstable'......it could 'roll off' the jack. The Draper item is a low pressure airbag. In the Fire Service, we changed to high pressure airbags some years ago because of this potential problem. You get a higher lift with low pressure system though.

I mainly stowed it because I got bogged down in Portugal a few years ago. This happened on a campsite where I was directed to a sandy site and had to get the campsite tractor to pull me out. It occured to me that I needed something in case I was alone and miles from help.

I still carry a standard jack and if on a hard standing, would use that to change a wheel.