Doubt this is in the right place but hey ho.
I know the axle can be raised and lowered by a switch but how does it work? Does the air lower it then a spring lift it? Toying with fitting a lifting axle on a 6x4 land rover
That’s how I have always thought they worked but thinking about it we have trailers with lift axles too. If they have no air pressure you would assume the lift would be up - but they remain down.
Usually some sort of airbag inflating against some variety of lever to lift it to prevent ride and handling issues.
For a Land Rover the axle would be light enough you could probably use one of those pneumatic rams they use on tipper tailgates
Own Account Driver:
For a Land Rover the axle would be light enough you could probably use one of those pneumatic rams they use on tipper tailgates
Would the bumps and ruts of the road not quickly deform the piston as it would have no dampening and take quite a pounding?
Use the air bags and axle from a p60 range rover, can’t see the point versus expense and effort to be honest
Just for the pure fun of it, I’ve wanted to build a 6x6 defender for years but it’s too much to do 6x6 so 6x4 seems the better option, just seems like it’d be better off roading if I could spread the weight that bit more
Personally I don’t think 6x6 or 6x4 would be much benefit of road, a set of unimog axles or lr axles with uprated half shafts and a decent flex out of the suspension.
Not knocking your idea, but I would keep the axle down as the fuel consumption saved would not regain the cost of fitting it. Also as been mentioned it would take a battering off road as I could not see the lift axle flexing as much as the other axles.
Still an interesting concept and Ido hope you give it a go and win, we need more fun in cars 
m1cks:
Own Account Driver:
For a Land Rover the axle would be light enough you could probably use one of those pneumatic rams they use on tipper tailgatesWould the bumps and ruts of the road not quickly deform the piston as it would have no dampening and take quite a pounding?
You would have to have the axle on airbags so a P38 Range Rover axle, as mentioned, once the bags inflated there would be no force to speak of transmitted to the ram. The ram would push action to raise and the bags inflating do the lowering you could either include a spring at the end of the ram or engineer it so the ram was not making contact with anything when fully retracted.
This is a typical truck set-up with the big central bag inflating to raise the axle:
Frost89:
Doubt this is in the right place but hey ho.
I know the axle can be raised and lowered by a switch but how does it work? Does the air lower it then a spring lift it? Toying with fitting a lifting axle on a 6x4 land rover
There is a huge spring that forces the axle down. The spring is so strong, it takes weight off of the drive axle hence the button that momentarily lifts it to gain traction. The air pressure lifts it up so if you lose air overnight, it’ll drop.
A fitter was killed once when he was working under one, the weight shifted somehow and the axle started to drop on him crushing his chest.
Air bag to lift the axle is a good idea, then it would just compress the shocks when lifted, but I do think it would just end up being a useless gimmick 
there is plenty of time before I die, the next landy is already earmarked as a 90 challenge truck
Dumb question time whilst on the subject 
If the trailor has a lift axle is that normal operated on the same switch for the unit or is it on the trailor itself?
And why does my phone auto correct trailer to trailor?
Big Jase:
Frost89:
Doubt this is in the right place but hey ho.
I know the axle can be raised and lowered by a switch but how does it work? Does the air lower it then a spring lift it? Toying with fitting a lifting axle on a 6x4 land roverThere is a huge spring that forces the axle down. The spring is so strong, it takes weight off of the drive axle hence the button that momentarily lifts it to gain traction. The air pressure lifts it up so if you lose air overnight, it’ll drop.
A fitter was killed once when he was working under one, the weight shifted somehow and the axle started to drop on him crushing his chest.
Huge spring ? Don’t think so ,the only spring I know of to force an axle down is where a air bag is fitted to a steel sprung axle to lift it normally after market or home made devises .most lorries now have 1 or 2 bags to lift and 2 suspension bags at the end of a short none suspension spring .
Ady Williams:
And why does my phone auto correct trailer to trailor?
Cos your phone is using American English. Change it in a settings menu - depends which phone you have.
Ady Williams:
Dumb question time whilst on the subject
If the trailor has a lift axle is that normal operated on the same switch for the unit or is it on the trailor itself?
It’s independent and uses load sensors to tell if it’s needed or not. It knows by how much air pressure it has to supply to the air bags to know if you’re heavy or not. They are normally operated by the feed from the ABS suzie line.
m1cks:
Ady Williams:
Dumb question time whilst on the subject
If the trailor has a lift axle is that normal operated on the same switch for the unit or is it on the trailor itself?It’s independent and uses load sensors to tell if it’s needed or not. It knows by how much air pressure it has to supply to the air bags to know if you’re heavy or not. They are normally operated by the feed from the ABS suzie line.
Really? I’ve never come across a lift axle on trailer that’s this technical! Ones I’ve used just have a push button on chassis like the brake and shunt button and axle goes up or down regardless of weight on trailer. Maybe there are more complicated ones out there like you describe but I haven’t seen them
switchlogic:
m1cks:
Ady Williams:
Dumb question time whilst on the subject
If the trailor has a lift axle is that normal operated on the same switch for the unit or is it on the trailor itself?It’s independent and uses load sensors to tell if it’s needed or not. It knows by how much air pressure it has to supply to the air bags to know if you’re heavy or not. They are normally operated by the feed from the ABS suzie line.
Really? I’ve never come across a lift axle on trailer that’s this technical! Ones I’ve used just have a push button on chassis like the brake and shunt button and axle goes up or down regardless of weight on trailer. Maybe there are more complicated ones out there like you describe but I haven’t seen them
Ours are all fully automatic and need no driver intervention at all.
switchlogic:
m1cks:
Ady Williams:
Dumb question time whilst on the subject
If the trailor has a lift axle is that normal operated on the same switch for the unit or is it on the trailor itself?It’s independent and uses load sensors to tell if it’s needed or not. It knows by how much air pressure it has to supply to the air bags to know if you’re heavy or not. They are normally operated by the feed from the ABS suzie line.
Really? I’ve never come across a lift axle on trailer that’s this technical! Ones I’ve used just have a push button on chassis like the brake and shunt button and axle goes up or down regardless of weight on trailer. Maybe there are more complicated ones out there like you describe but I haven’t seen them
There are.
It’s not actually that technically difficult to do. All trailers will already have a load sensing function of some sort to control how strongly the brakes are applied in relation to the load carried. This is done by either a load sensing valve (there’s a long thread somewhere where the Bking twerp argues they don’t exist) or on newer trailers there’s a pressure sensor in the modulator block that does the same but electronically.
Own Account Driver:
switchlogic:
m1cks:
Ady Williams:
Dumb question time whilst on the subject
If the trailor has a lift axle is that normal operated on the same switch for the unit or is it on the trailor itself?It’s independent and uses load sensors to tell if it’s needed or not. It knows by how much air pressure it has to supply to the air bags to know if you’re heavy or not. They are normally operated by the feed from the ABS suzie line.
Really? I’ve never come across a lift axle on trailer that’s this technical! Ones I’ve used just have a push button on chassis like the brake and shunt button and axle goes up or down regardless of weight on trailer. Maybe there are more complicated ones out there like you describe but I haven’t seen them
There are.
It’s not actually that technically difficult to do. All trailers will already have a load sensing function of some sort to control how strongly the brakes are applied in relation to the load carried. This is done by either a load sensing valve (there’s a long thread somewhere where the Bking twerp argues they don’t exist) or on newer trailers there’s a pressure sensor in the modulator block that does the same but electronically.
How dare you cast nasturtiums on my hero.