I have just bought a 2015 Majestic sierra. I want to under slung the axels and fit a semi off-road tyre to give me a bit more height off the ground. Any advice please.
Oh, and where the leaf springs are is how it is slung. So a normal axel has the leaf springs underneath so the axel is underslung. Putting the axel under the leaf springs makes it an overslung.
As for tyres, caravans use light truck tyres for the weights. The compliance plate will have details about tyre sizing and weights etc. Just ask at Bob Jane Tmarts about an All Terrain (AT) that meets the specs.
I thought the OP is talking about fitting the axle "under" the leaf spring . To raise height ?? Keep in mind the leading or trailing brake systems on drum brakes . If turning them ?
Hylife. SOME? axles have camber built it. If rotating it. look along length first for any bend in it.
Axles also have toe-in. I cannot tell for sure if this is deliberate, or accidental, but they do have toe-in built into them. My Jayco had the axle delivered with toe-out. About 9 mm at the centre of the tread. The tyres wore out after 18000 km. I cannot understand why... I took it back to Jayco and after a lot of heated discussion they arranged for it to be straightened. Short story made long, that didn't work and after wearing out another 2 sets of tyres (with toe-in this time), I contacted Al-Ko who made the axle and they replaced the axle for free. Even that axle has about 5 mm toe-in, but thusfar the tyres seem to be wearing OK. The Al-Ko man said that some toe-in was needed to provide stability for the towed vehicle. I remain to be convinced on that one. The axle is made from a solid square steel bar with the stub axle welded on top of the bar, not the end. Being a circular section against a flat surface, there is a lot of weld required to fill the gap, and shrinkage of the weld will cause distortion - hence the toe-in.
If you flip your axle, any toe-in will become toe-out and you will wear tyres. Also, the plates to locate the centre bolts may need some attention. If you keep the orientation of the axle the same ie original right side goes back on the right, you will be OK. As said above, you will need to undo your brake backing plates and reposition them. No big deal there. Putting the axle on top of the springs has one minor benefit - the U bolts no longer are carrying the weight of the trailer. I am yet to see a U bolt fail, so maybe this is of no consequence. Simple check - measure the toe-in or out of the axle and if there is any, be aware of it. I reckon up to 2 mm should be OK for toe-out. If more, get the axle bent in the centre of it and hopefully you will not have problems with tyre wear. Another alternative would be to cut the locating plates off the axle and weld them on the other face of the axle in the same place so you don't upset the angle of the towing ( the trailer does not track crooked).
-- Edited by erad on Monday 15th of May 2017 11:14:34 AM
You can buy U plates with a hole drilled in for the spring centre bolt to locate on a square beam axle.
They are 4 dollars each from a Martins trailer parts.
They also make axles to order. Good price too.
Kezngaz
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Hylife. SOME? axles have camber built it. If rotating it. look along length first for any bend in it.
In Australia, a beam axel should have no camber at all. Beam axels are rated to NOT bend or flex up to a maximum weight. This is dependant on the thickness of the beam, and if it is round or square, and if it has stubs. If a beam flexes then it is being overloaded.
Manufacturers of beam axels specify the maximum distance from the ends of the axel, that the leaf springs must affixed within. If a beam axel has what appears to be camber then it is in reality bent (damaged) and needs to be straightened.
There is however a theoretical perfect toe out on a beam axel dependant on the distance from the hitch point which provides accurate tracking.
Take your van to a heavy vehicle wheel aligner if you are at all concerned about true tracking and tyre wear.
I thought the OP is talking about fitting the axle "under" the leaf spring . To raise height ?? Keep in mind the leading or trailing brake systems on drum brakes . If turning them ?
The OP unfortunately asked about underslung axels.
The axel if in its original configuration is most likely already underslung. What the OP requires is feedback on those that have "overslung" their axels.
Pieter wrote:
....I want to under slung the axels and .....
Also mentioned in my post is that one needs to simply unbolt the brake backing plates before the rotation, flip the cable lever over and re-bolt the plates back on after the rotation. This keeps the original design of the brakes of magnets down and of the axel contained within the leaves.
Hylife wrote:
The brake back plates are unbolted before rotation and rebolted after and you will have to flip the brake cable lever.
Have to ask ? Would longer spring shackles work ? Your after extra height rather than firmer spring ? Note the question marks guys .. I'm not stating fact I'm working it with you .. I assume you need space due to fitting higher wheel dia ? Have similar issues with my car carrying car trailer . Bigger dia wheels makes car loading an issue plus opening the doors of car once loaded over guards .. just the problem is the other way around ..
Pieter can you answer a few questions so we can provide better advice for you.
Is your van currently fitted with the correct tyre sizes according to the compliance plate?
Is your van a single or tandem axel?
Do the leaf springs using eye hangers front and back, or only one at the front and a slipper at the back?
Another way. if mounted front rear shackles on spring packs..
Get some extended shackles for ends and bolt them in on new bushes.
That'll give you lift with NO movement of parts.
We do\did it to leaf suspensions on a lot of older 4wd's.
Just use thicker plate and box sect to weld up with.
Worked well on them. Why not vans that are only towed.
IE NO Torque flex.
