Trailer Weight Distribution Hitches

A weight distribution hitch may be required if the centre of gravity of your trailer is too far forward, which is sometimes unavoidable. This will cause poor handling during breaking and accelerating and increases the risk of accidents.

What is a weight distribution hitch?

A weight distribution hitch, also known as a load leveller or level-ride, maintains the vehicle in the normal position by altering the weight distribution of the loaded trailer. It does this by altering the point where the trailer load is transferred to the tow vehicle.

If the tow ball weight of the trailer affects the rear of the tow vehicle, you may experience a seesaw effect where the front of the vehicle is lifting, reducing the weight on your steer wheels. As a result, effecting traction, steering control and braking. 

What are the components of a weight distribution hitch?

Before we dive into the components of a weight distribution hitch, it is important to provide an overview of the entire setup, including how the trailer is ultimately attached to the tow vehicle. 

1. Trailer hitch: A trailer hitch is bolted to the underside of the tow vehicle at the rear, a trailer hitch provides a tube for attaching a hitch receiver (or ball mount for normal towing with a weight distribution hitch). There are many different types of trailer hitches.
2. Hitch receiver: This is the receptacle (hollow) part of the trailer hitch which accommodates different inserts such as ball mounts, or in this case, a weight distribution hitch shank.
3. Weight distribution hitch:
   • Shank: This part acts as an adjustable mount that is inserted into the hitch receiver and can be moved up or down depending on the height of your tow vehicle. 
   • Head assembly: The weight distribution hitch ‘head assembly’ attaches to the shank, providing a place for the ball mount of your trailer and provides the spring or sway bar attachment points. 
   • Spring/sway bars: One bar is attached to each side of the drawbar to help level the trailer by distributing the weight evenly between the trailer and tow vehicle’s axles.
   • Frame brackets: These are used for attaching the spring/sway bars to the frame of the trailer. 

How do I know if my trailer needs a weight distribution hitch?

As your trailer approaches half the weight of your tow vehicle, you should start considering a weight distribution hitch. 

Whenever a trailer is hooked to your vehicle, a certain amount of weight is applied to the tow ball and rear axle. This weight is known as the tongue weight (TW) or tow ball weight. In more technical terms, TW is the portion of the aggregated trailer mass (ATM) supported by the tow vehicle’s hitch. TW should be kept to 10-15% of your trailer’s ATM.

If you are still unsure, measure the distance from the wheel arch to the ground, and from the front of the trailer to the ground, before and after hitching. A weight distribution hitch is recommended for a difference of 5-10 mm after suspension compression.

Does a weight distribution hitch increase my trailer’s towing capacity?

No – a weight distribution hitch does not increase your towing capacity. Your towing system is only ever as strong as its lowest-rated component, which is why you should never try to ‘push the limits’ when towing. 

Our thoughts on weight distribution hitches

Ultimately the most desirable outcome is that your axle placement is correct for your trailer and the load you are hauling.

Your tow vehicle also needs to be suitably rated for both the tow ball weight (tongue weight needs to be less than the maximum rating of the tow hitch) and combined vehicle mass (trailer included). In other words, is your vehicle suitable for the trailer you are towing.

Using weight distribution hitches should be done with caution, keeping in mind that they alter the distribution of weight. If this hasn’t been accounted for in the engineering of the trailer, it can lead to early fatigue in your drawbar and ultimately failure.

Note: most trailer manufacturers do not account for altered forces through the use of a distribution hitch. 

Weight distribution hitch summary

To avoid accidents when towing, plan ahead to make sure both your vehicle and trailer are adequately rated. If you have been experiencing towing issues such as:

• Sagging in the rear of your tow vehicle,
• Tow vehicle headlights pointing upwards,
• Trailer sway, or
• Difficultly steering or stopping while towing,

it may be time to consider a weight distribution hitch.