The Tow Hitch is one of the most overlooked components of a Caravan. It’s vital for your passengers and your vehicles safety. Used improperly, or if not maintained, the results of a Tow Hitch not doing its job has disaster written all over it.
Styles & Purpose and what really counts? Yes, there are quite a number of varieties on and off the road today. Let’s look at the ones I’m currently servicing and try to answer a few of your questions.
Once upon a time, there was only one type of Hitch on the roads. A ridged Standard Plunger Ball Mount Coupling. Today the 50mm ball coupling is the IOS standard for trailers up to 3500kg ATM.
The basic 50mm ball coupling is a very simple device. It consists of the body casting, locking handle and a spring-loaded locking tongue entering the main casting at 45°. Also attached is an adjusting bolt and locking nut designed to take up excess clearance and accommodate wear of the ball or coupling, ensuring a secure fit.
A ball coupling does not need much maintenance, but it is important to cover two elements. Firstly, the coupling cavity should be lightly greased so that it can swivel freely and avoid excessive wear on the towball and coupling. Secondly, any excessive slack in the coupling when it is secured on the ball should be taken up with the adjusting bolt.
The Standard Plunger Ball Mount Coupling is a quick release plunger coupling. They are not considered to be strong enough to withstand the rigors of off-road use.
If you have an Off-road Caravan and plan on tackling the Gibb River Road or a Touring Caravan and plan on travelling on rough corrugations through the Murchison, you will want a coupling that isn’t a 50mm ball.
I’m retrofitting a number of the Vehicle Components’
DO35 or DO45 to different Caravans. They have been developed without a ball, The Vehicle Components hitches have locking mechanisms that are easy to engage and they have a great range of movement that allows them to articulate freely.
This is introduces in a huge factor of Safety, so that if a caravan rolls, you have a much better chance of the caravan being able to spin freely off the car with only safety chains and, perhaps, weight distribution hitches becoming involved.
The maintenance involved in these couplings is relatively easy. Regular checks and lubrication of grease points should be done to ensure the coupling’s continued performance and longevity. Greasing the coupling body is as simple as pumping grease into the grease nipple located on the housing of the body.
Service intervals vary depending on terrain being tackled but on average the coupling body should be greased every 10000 km. The pin should be kept clean and have a light smear of grease.
Hitching Demonstration for Vehicle Components DO35
The most Beautifully designed all round Caravan Hitch would be the Hitch-Ezy an Australian Design Rule compliant Hitch for up to a 5000kg Caravan. It is aimed primarily at owners of heavy-duty off-road caravans and fits on standard tow bar mounting points.
It provides a full range of articulation (90 degrees up and down and unlimited left to right) plus 360 degrees rotation in the long axis of the trailer. But unlike some pin-type couplings the Hitch-Ezy utilises a rotating unlocking ‘lid’ with a self-centring characteristic that connects with the ease of dropping onto a standard 50mm tow ball". The Hitch-Ezy also has an automatic double locking mechanism. A padlock can be used on the secondary lock as extra back-up and is able to perform through most of its range of articulation with the padlock in place. This is possibly the only coupling on the market that can be released under any load.
The Hitch-Ezy uses O-ring seals to keep dust and water out of the mechanism, and also comes with an aluminium dust cover and plug to keep it protected when not in use. The grease nipples are placed at the rear to prevent damage and it is easily maintained and greased.
Recently, Hitch-Ezy has released a new version of its hitch.
The latest design features automatic primary locking and a redesigned automatic secondary locking system, a main body and stem-to-yoke junction whose integrity is not weld dependent, a tow-pillar subject to ONC (oxy-nitro-carburisation) process that stress relieves the machined part, hardens the bearing surface, inhibits rust and avoids hydrogen embrittlement and a system that doesn’t allow people to hitch the pivoting head onto the tow pillar upside down.
I am yet to see one of the new release hitches, but will report back when I do.
Another off-road hitch is the HYLAND, which uses a ball coupling with a difference. The hitch is manufactured to give the ball full articulation. It also has full 360 ° sideways swivel & is far superior to the old ball hitch in off-road situations.
The Hyland hitch must be used in conjunction with a 3.5
tonne ball which has a higher stem than the standard 2.5 tonne ball. This allows for proper fitment of the Hyland hitch over the ball allowing clearance without fowling the tow tongue.
Unfortunately, Australian trailer hitch manufacturer Hyland Trailer Couplings has closed its doors in Brisbane after more than two decades of local manufacture. If you have one, you are lucky, but repairing damaged hitches is no longer an option and problems tend to occur after a bit of wear with these hitches.
Maintenance involves a regularly check for any movement in your hitch by placing a spare towball in the hitch and forcibly try to move it about. Have a look at the tongue in the hitch cup to ensure that it is not 'rounded' where it is supposed to sit under the ball. Grease this hitch regularly.
What Really Counts?
Regardless of what make or model of Tow Hitch you have, each is mounted onto the Caravan A-Frame, with either Bolts or it has been welded on.
I advise against welding for a two reasons. The heat penetration created in the process of welding, will weaken the chassis at that point and if used off road, unless it has been put there by a coded welder, it will eventually part from the A-Frame.
I have come across off road Caravans on two occasions,
where the welding has parted from the A-Frame. Both times they were in the middle of nowhere. One of the owners had persevered with just the chain attachment, you should have seen the state of the back of his vehicle!
Bolts are the perfect method of securing a coupling. They can be checked and tightened. They can also be replaced very easily and carried as a spare. However, what I am finding out on the Field gives me reason for concern for your safety and that of your Family.
Let’s use the McHitch as an example. The mounting bolt holes are elongated, with a maximum diameter of 12mm. Most manufactures drill out the A-Frame Hitch Plate to 14mm. This is a good thing as 14mm bolts should always be fitted. However, they don’t like to waste time drilling out the McHitch bolt holes to 14mm, and subsequently fit 12mm bolts.
Firstly 12mm bolts are too small for the Caravan towing Application, especially off road. Secondly, when the nuts start to loosen off, which they do, the 12mm bolts start to move around, ever so gradually, until they shear off. This will ruin a holiday at best.
If you’re unsure of what type of Bolts secure your Hitch, or are unsure of how many Newton Meters of Torque needs to be applied, have your Caravan Serviced Annually by Westcoast Trailer and Caravan Services, it is all part of their Annual Inspection Checks.
Westcoast Trailer and Caravan Services also supply and fit all models of quality hitches. Call them for a Quote.
Comentarios