Upgrading your caravan or camper trailer suspension

Tuesday, January 01, 2013

Why upgrade your caravan or camper suspension? There are two main reasons. The first reason is to increase the payload so you can carry more goods, and the second reasons is to improve the ride and handling of your rig. Pick carefully and you should achieve both.

If you want to increase the offroad capability of your van this is also possible but remember many on-road vans are not built to the same standards as a genuine off-roader.

Often caravaners have spent many years getting their van just right and don't really wish to change to a newer van. Upgrading can give new life to an old favorite.

It can also be advantageous to buy an older cheaper van and start the renovation by upgrading the suspension to something such as an independent coil.

What's involved?

The project is really in two parts, the first is the actual fitting of the suspension and axles, the second part is to sort out the paperwork that will allow you to get a new VIN plate (if the vehicle is yet to be registered) or a modification plate and register the vehicle legally.

Possibly the easiest upgrade is the simple swapping of springs such as increasing the number of leaves in a leaf spring setup, or swapping the coils in an independent. With an independent such as the Cruisemaster coil an increase from say an ATM of 1600 to 2000kgs can take as little as half an hour.

What needs to be considered?

A new spring is likely to raise the ride height of the vehicle slightly and firm up the ride. However a few other issues will be addressed if you wish to consider raising the ATM. This is mainly due to legal requirements. You will need to get proof that your drawbar will be suitable at the new ATM rating. This will require an engineers calculation, however contact the original manufacturer of the vehicle and he may well be able to confirm that this has already been done and ive you the information for you to obtain a modification plate. Your state registering authority will also need to be informed and their requirements should be confirmed before the project is started.

Other issues you will need to check are whether any changes need to be made to the type or size of brakes and safety chains particularly if the new ATM takes you into a different category. Also don't forget to check the ratings of the wheels and tyres. Your coupling may also need to be changed.

If you wish a more major change, say from a traditional leaf and axle setup to a coil independent then a bit more planning will need to be done. Upgrading to a non-load sharing independent suspension from a load sharing leaf will require the wheels and tyres to be checked for the additional 20% load carrying capacity required by legislation.

Other things to consider now will be how the new system will effect the wheel arch design so check the new ride height and axle spacings if it's a tandem setup. If you are replacing the existing wheels and tyres with bigger ones then you will need to take this into account. Check the offset of your new wheels. Don't forget the height change on the awning.

If you need to perform any welding on the chassis check the routings of electrical wiring and hoses to make sure these will not be damaged. You might have to move the position of water tanks so check that the draw bar load will not be adversely affected by this change. Moving heavy items from above the axles to outside the axle area can also affect the handling of the van.

Upgrading to an independent suspension can be carried out in one of two ways. The first is a cut and shut method where the suspension is directly welded to the old chassis. This may require fitting of new cross rails and the fitting of shock absorber mounts. A second way is to mount the suspension to a frame and fit the frame to the chassis.

With the increase in popularity of independent suspensions we are performing more and more retrofits. Some of these are on older units and some are on brand new vans straight out of the show room.

Air independent suspensions can also be retrofitted which will give the advantages of independent suspension and allow the optimum ride height to be set no matter what the load. This will require the fitting of a control system which can include compressors and manual and/or automatic height adjustment if required.

If you are considering an upgrade to your rig give us a call we will be happy to advise.