A crucial factor in safe and secure towing is a level rig – and this all starts with the weight distribution hitch!
WORDS AND PHOTOGRAPHY BY GRANT HANAN, ADDITIONAL PHOTOGRAPHY BY CARAVAN AND MOTORHOME ON TOUR
Towing is all about balance and levelling your load. If you get it wrong, your towing experience is full of stress and can be downright dangerous. Get it right, and you can enjoy the drive to your next destination, knowing that your setup will hold the road and brake smoothly. The most important component for balancing your van correctly is a weight distribution hitch (WDH). Let’s take an in-depth look at exactly what they do, and how to ensure yours is set up perfectly.
WORKING OUT WHAT YOU NEED
Important: Both RV and vehicle need to be loaded as they will be when you are travelling.
1 Set the fully-loaded tow vehicle and the fully-loaded RV on a large flat surface.
2 Have the vehicle slightly forward of the RV and uncoupled.
3 With the aid of a spirit level, use the jockey wheel to get the RV to a level position.
4 Using a straight edge tape measure as an aid, record the following measurements:
• A&B – the distance between the ground and the top of the wheel arch on the tow vehicle.
• C&D – the distance from the RV to the ground, front and rear.
5 From the ground, measure the distance of your vehicle’s tow ball height and your RV’s coupling. Make any necessary adjustments to have the tow vehicle’s ball hitch equal to or slightly higher than the caravan coupling.
Note: this adjustment depends on the type of hitch receiver you have, so follow the manufacturer’s recommendations for this step.
6 Once set at the correct height, hitch the RV to the tow vehicle.
7 Repeat step 4 and record the measurements.
8 Complete the calculation by subtracting the hitched measurement from the unhitched measurement.
9 With this diagram completed, you can now look at purchasing a weight distribution hitch that can correct the geometry.
If you see a towing setup where the vehicle’s rear sags and its front is raised, you immediately know that a problem exists with weight transfer. In other words, there’s too great a load being placed on the rear of the vehicle, causing a “see-saw” action at the hitch point. This results in less weight on the front wheels. Your RV and towing vehicle should be level for optimum safety, stability and vehicle control.
3 REASONS FOR NOT BEING LEVEL
1 Uneven caravan load resulting in exceeding tow ball weight specifications.
2 Incorrect tow ball height compared to the RV coupling.
3 Improper setup of towing equipment.
A tow vehicle’s ball weight should be between 8-12% of the mass of the RV being towed. The caravan industry regards 10% as an appropriate figure.
KNOW YOUR SETUP WEIGHT
You need to know the exact total ATM and ball weight of your RV. To get an accurate measurement, visit a public weighbridge when your RV is fully loaded with all on-board water, gas, food supplies, clothing, etc. Your vehicle should have its fuel tanks full and its rear loaded.
From trip to trip your payload may vary, so regularly check your ball weight using ball weight scales.
WHAT IS BALL WEIGHT
Ball weight is best described as the actual amount of effort or weight being pushed directly downwards at the A frame coupling from your RV onto your tow vehicle.
Think of your RVs’ wheels as the axle of a see-saw with the heavy end tipping onto your vehicle’s tow ball. This in turn lowers the rear of your tow vehicle. It is an extremely important factor! If the tow ball weight is too light, your van may bounce, drift and behave poorly, making driving stressful. If it is too heavy, your tow vehicle’s suspension is placed under strain, your steering becomes light, and braking efficiency is decreased.
MAKING ADJUSTMENTS AND APPLYING TENSION
1 With the weight distribution hitch now attached to the vehicle, we return to our setup and pick up from step 9. Start to apply tension to the spring bars as per the manufacturer’s instructions. (The method of tension used depends on the type of system purchased).
2 Our aim is to adjust the tension required to rebalance the difference between the vehicle’s front and rear wheel arch measurements (A&B) within 10mm difference.
With adjustments achieved within 10mm, we record these measurements for future reference. TIP: mark or label the settings for ease of re-use.
As your RV’s ATM may change during your journey, ensure you review these measurements to obtain optimum stability.
NOTE : This information is provided as a general guide due to the many varieties and types of weight distribution systems. Always follow the manufacturer’s instructions.
EXPERT SETUP TIPS
1 Always calculate a WDH system using the knowledge gained from measuring your setup fully loaded. If you are paying for installation, ensure the RV and vehicle are both fully loaded before the WDH system is fitted.
2 When arriving at a site that requires tight manoeuvring, remove the tension bars for safety and to prevent damage to your RV and tow vehicle.
3 Some WDH systems can be used on good gravel roads, but if you are encountering severe departure angles, aggressive potholes and corrugations, remove the tension bars. This will avoid damage due to excessive loading.
Question – Do I still need a WDH if I fit airbags to the rear of my vehicle?
Answer – Yes. Airbags help to level out your vehicle, but only a WDH system distributes the load over the vehicle and to the front wheels.
Question – If I fit a WDH do I still need to be concerned about ball weight?
Answer – Yes. You are bound by the Vehicle and RV’s specifications. You cannot legally exceed these. A WDH will assist to transfer the ball weight over the vehicle’s four wheels.
WEIGHT DISTRIBUTION SYSTEMS
Weight distribution systems are often called levelers, tension bars, equalizers, or loadsharing distributors. Many forms and types are available. When set up correctly, these systems apply/redirect some of the caravan’s ball weight along the tow vehicle’s body onto its front wheels. If the weight distribution hitch (WDH) is fitted and tensioned correctly, the outcome is a more balanced unit. The tow vehicle and RV are level, so wobbling and swaying are minimised.
Having your RV set up correctly with the right WDH system will make your towing experience much more enjoyable, but correctly fitting and making adjustments to it is a skill. If you are unsure, seek advice from a towing expert. The time and effort you spend in getting the system right from the start will save you in the long run.