Should a Caravan be level when towing?

Q: Should a caravan be level when towing?

A: Having your caravan level when it's parked is a simple one: Without that, you're in danger of sliding or rolling out of bed. But on the move, particularly at highway speeds, having a level (in a side view) caravan can be extremely important. At other times, it's purely an aesthetic and aerodynamic consideration. But knowing which is which might save your life.

The truth is not all caravans need to be level to be safe to tow at highway speeds. But some do, and those are tandem-axle vans which do not have a load-sharing suspension arrangement.

In such a caravan or trailer, having a non-level attitude can lead to some seriously dangerous problems including unpredictable handling characteristics at any speed.

This can be made even worse if the driver makes a sudden input or the road is windy and/or bumpy. Even correcting a swaying caravan can cause all sorts of problems if the wrong type of van is not level.

So, how level is level enough? Generally speaking, a tolerance of about five degrees up or down at the front is okay, but any more than that starts to stretch the friendship in regards to geometry and, therefore, stability.

Digging a little deeper, we need to know what suspension types are, and are not, load sharing. Independent coil-spring systems on a tandem-axle van - where the front and rear units on each side of the van are not inter-connected - are not load sharing, and therefore the van must ride level to be towed safely.

In this case, the front and rear suspension units of an unlevel van will be loaded more to the front or rear. In the former case, this will decrease the effective wheelbase of the rig and lead to reduced stability.

So, how level is level enough?

Rocker-arm leaf-sprung suspension systems on a tandem-axle van, on the other hand, are load-sharing, so the attitude of the van is less important as it won't affect stability.

Which brings us to the difference between level and balanced. Any type of caravan, regardless of whether it's level or not, must also be balanced. That is, the load inside the van must be distributed correctly with heavy items like water tanks located low and (preferably) over the axles, rather than high up and at either extremity of the caravan.

By far, the biggest factor in how level a caravan sits is the height of the tow-bar to which it's attached. The ride height of the towing vehicle is not the issue here; it's all about the tow-ball height relative to the van's chassis.

Logically, then, how to level a caravan for towing revolves around altering the height of that tow-ball. You may find that you need to source a tow-hitch with an adjustable tongue height, but another factor is having the correct inflation pressures in all the van's tyres, according to the load on each tyre (not just the inflation recommendation on the trailer's build-plate).

Any type of caravan, regardless of whether it's level or not, must also be balanced.

Many people think a Weight Distribution Hitch (WDH and also known as load levelling bars) will alter a van's level or otherwise, but the truth is that these are only designed to transfer some of the tow-ball loading to the tow vehicle’s front axle. Level riders for towing are more of the same. Some car-makers do not recommend or even permit the use of these hitches.

So how do you check your van's level? One of the best techniques is to hitch everything up and park on a piece of level ground. Then, take a tape measure and measure the distance from the ground to the bottom of the chassis rail at the front and rear of the van.

The closer those figures are to being equal, the closer to dead level the caravan is sitting. As hints and tips go, this is the pick of them.

You can also fit a caravan spirit level to the drawbar but, to be honest, these are more useful for ensuring the van is level when parked (so the water in the sink drains fully and you don’t fall out of bed) than the actual ride-level of the rig.

So how do you check your van's level?

There's also, believe it or not, a caravan leveller app but, again, this is designed for levelling the van once it’s parked in place at the beach and not an automatic system for ride-levelling in real time.

Here's the bottom line: All caravans should be level when they're being towed, but a tandem-axle van with a non-load-sharing suspension system MUST be level.