The purpose of a trailer hitch is to hook up a trailer to a vehicle.
A basic distinction is made between rigid, removable and swivel hitches to suit the requirements of the user.
A rigid hitch is usually the least expensive type and is particularly suitable for regular use. It is permanently installed and cannot be removed.
A removable hitch offers far greater flexibility: After removing the neck there is generally nothing left to be seen of the hitch. Removable hitches are ideal for motorists who only use a trailer hitch occasionally to tow a trailer or for mounting a bike rack.
Swivel hitches are convenient and easy to use. The hitch stays under the car's bumper until it is needed. It can be swivelled out electrically or manually when required.
A trailer hitch can be retrofitted at any time if a vehicle is licensed for use with a trailer. The permissible trailer loads for a given vehicle (the load which a vehicle is allowed to tow with a trailer) are indicated in the registration documents (braked trailer load: Field O1, unbraked trailer load Field O2).
Extra information specifically for the vehicle concerned is contained in the space for remarks. If no trailer load is given for a vehicle, this means the vehicle is not approved for towing a trailer! Manufacturers of trailer hitches have no influence on the information contained in the registration documents.
Exceeding the trailer load or using a trailer hitch in a manner contrary to the specifications constitutes a major safety hazard.
A trailer hitch is a robust steel component but nevertheless requires regular upkeep, inspection and maintenance.
Signs of damage or severe corrosion may mean that a trailer hitch is no longer roadworthy.
Regular inspection is particularly important if a vehicle comes into contact with salt, as this is extremely aggressive. Without regular care, salt may seriously weaken parts of the trailer hitch and lead to failure of the hitch.
To ensure proper operation, the neck of a removable trailer hitch and the receiver tube must always be kept clean. Regular maintenance of the mechanism is therefore imperative. The lock should only be treated with graphite. It is also a good idea to regularly apply resin-free grease or oil to the bearing surfaces, sliding surfaces and balls. This additionally provides extra corrosion protection.
When cleaning a vehicle with a steam cleaner the neck must be removed and the plug insert fitted. If grease is applied to the inside of the receiver tube before fitting, the plug insert will be "sucked in" and will then remain firmly in position. The actual neck should never be treated with a steam cleaner.
IMPORTANT: The ball mount should be greased before hooking up a trailer. The grease or oil must however always be removed from the ball mount before fitting a bike rack on the trailer hitch! The ball should be protected with a cover when the trailer hitch is not in use.
Removable necks should only ever be repaired and dismantled by the applicable manufacturer. It is advisable to replace extremely worn or corroded necks. If the diameter of the ball mount is less than the legally prescribed minimum of 49 mm at any point, the mount must be replaced.
It is generally not advisable to purchase a used trailer hitch as there is no way of knowing how it has been treated in the past and what condition it is in. Second-hand trailer hitches often have worn elements and come without any fitting instructions.
At worst, the hitch may have suffered accident damage in the past. Hairline cracks or fractures can often not be detected "with the naked eye".