Installation check
Retrofitting a trailer coupling – requirements
In most motorhomes, a trailer coupling can be retrofitted without any problems. In addition to sufficient engine power, the key factor is the mounting options on the chassis. Therefore, the first step should always be to inspect the underside of the vehicle.
Motorhomes are typically built from a vehicle chassis with an additional living body mounted on top. The body of the motorhome usually extends beyond the length of the chassis. The illustration shows that a trailer coupling (tow hitch) may not fit directly, as the coupling ball would end up underneath the body.
For this reason, the gap between the end of the chassis and the end of the body must be bridged using a frame extension. The trailer coupling or the mounting system for a cargo carrier is then installed on this extension. This gap is referred to as the rear overhang.
Frame details
The load-bearing frame extension
If a usable, upgradeable frame extension is already installed from the factory, only the appropriate trailer coupling is required. Our specialists have access to an extensive database listing almost all motorhomes produced in Europe. This allows us to identify not only the correct trailer coupling but also the appropriate frame extension, if none is already installed.
However, since motorhomes are individually equipped, it may be necessary in some cases to relocate the wastewater tank, modify supports, or adjust add-on components. In such cases, a professional workshop should be consulted.
Strength values
Key factor: the D-value
The decisive factor when selecting the correct trailer coupling is the D-value of the design. The D-value is a measure of the strength of the towing device and is calculated using a fixed formula.
However, several factors play a role: the permissible total vehicle weight and the permitted trailer load specified by the vehicle manufacturer. It is therefore important to distinguish between whether a vehicle has an approved towing capacity and whether the D-value of the coupling is sufficient. Both requirements must be met.
The permissible trailer load is usually already stated in your vehicle documents, even if no coupling is installed. If you are unsure which towing capacities are approved for your motorhome chassis, we will be happy to assist you. Using our extensive databases, we can determine the required specifications. Simply contact us.
Axle loads
Pay attention to rear axle load
When using a trailer coupling on your motorhome, the rear axle load of the vehicle increases due to the vertical load acting on the coupling ball. Before using a trailer coupling, you must ensure that the rear axle load is not exceeded.
You can calculate the rear axle load of your motorhome using the following formula:
:contentReference[oaicite:0]{index=0}Where applicable, ensure all values are correctly taken from your vehicle specifications before performing the calculation.
Calculation example
Example calculation of rear axle load
If the wheelbase (R) of your motorhome is 2500 mm, the rear overhang (Ü) is 1100 mm, and the vertical load (S) is 75 kg, the resulting increase in rear axle load (F) due to full utilization of the vertical load acting on the coupling ball would be 108 kg.
Legal requirements
Towing capacity
Before attaching a trailer, the first step is always to check the vehicle documents. The maximum permitted towing capacity of the vehicle is stated in the registration certificate (part I and II). Important: Not only the towing capacity of the towing vehicle is relevant.
In some cases, there is an additional entry in the vehicle documents that limits the total train weight of the combination. This value is often lower than the theoretical sum of the vehicle’s gross weight and its maximum towing capacity. This means that if the full towing capacity is used, the towing vehicle must not be fully loaded.
This regulation has a safety reason: the combination must be able to start five times within five minutes on a 12% incline without any component failure. In addition, the chassis and brakes of the towing vehicle must be designed to safely control the combination.
Where is the towing capacity stated?
New vehicle registration document (Certificate of Registration Part I): You can find the towing capacity in the Certificate of Registration Part I. Field O.1 specifies the permitted towing capacity for a braked trailer, while field O.2 specifies the capacity for an unbraked trailer.
If you are not entirely sure what your motorhome is allowed to tow, please contact our service team. We will be happy to help you determine the correct towing capacity.
Decades of expertise
Linnepe: your expert for motorhome trailer couplings
Kurt Linnepe developed the first trailer coupling for motorhomes in the 1980s. When it comes to towing systems and trailer couplings, Linnepe has since been at the top of the list of specialists. More than 30 years of expertise go into every towing system.
Development and production at a single location ensure that our engineers can apply their know-how and experience in a targeted way. Today, Linnepe offers the right trailer coupling for all common motorhomes. Linnepe motorhome trailer couplings are made of steel and are permanently resistant to corrosion.
All trailer couplings for motorhomes from Linnepe come with EC type approval and are therefore exempt from registration. Linnepe’s goal: minimum weight with maximum load capacity and functionality. For all common motorhomes, we offer a suitable towing solution—see for yourself and find the trailer coupling that fits your motorhome.
Advantages at a glance
Quality features of Linnepe trailer couplings
Extreme durability and robustness. Corrosion-protected. No registration required thanks to EC type approval. Can be mounted in addition to carrier systems.
Combination options
Even more flexibility when travelling: trailer coupling plus carrier system
Did you know? In addition to or instead of a trailer coupling, you can also install a carrier system on your motorhome. Our towing systems usually already provide a mounting base for a cargo system or rear carrier. With many of our tow bars, you can choose between a fixed or detachable ball.
Do you have questions?
Expert advice & service
Service Center South (Burgheim)
We serve customers from southern Germany at our Service Center South.
Learn moreService Center / Factory Installation (Ennepetal)
We serve customers from northern Germany at our Service Center.
Learn moreFitting a tow bar
Frequently asked questions
The D value of the design has a decisive influence on choosing the right trailer coupling. The D value is the measure of the strength of the pulling device, which is calculated using a fixed formula. However, several factors play a role. DetailedYou can find information in our guide: Trailer hitch motorhome guide
The maximum trailer load of your vehicle can be found in the vehicle registration document at:
O.1: braked
O.2: unrestrained
To check whether we can offer this towing capacity, please use our Contact form.
Yes, you can generally install the trailer hitch yourself as the relevant installation instructions are included. However, we recommend that the installation be carried out by a qualified person or a specialized workshop to ensure correct assembly, compliance with all technical specifications and perfect function and safety.
Depending on the vehicle, it cannot be ruled out that the ground clearance in the rear area will be slightly reduced by installing a trailer hitch. The exact effect depends on the respective vehicle model and the installation situation.
Each motorhome is individually constructed. So that our service team can check whether your vehicle needs a frame extension, please use our Contact form and tell us your vehicle-specific information.
The total towing weight of the vehicle remains unaffected if the load is increased.
This may result in the trailer load being reduced due to the additional load.
Example:
Total train weight: 5500kg
Before loading: 3500kg + 2000kg = 5500kg
Towing vehicle: 3500kg
Trailer load: 2000kg:
Total train weight: 5500kg
After loading: 4090kg + 1410kg = 5500kg
Towing vehicle: 4090kg
Towing capacity: 1410kg
The D value of the trailer coupling must also be taken into account:see D value
Motorhomes:
The existing trailer hitch remains unaffected when a Linnepe load carrier is installed.
If you would like to use the trailer hitch, the Linnepe load carrier can be dismantled in a very short time without tools using quick-release fasteners.
It is not possible to use the trailer hitch and load carrier at the same time.
Van:
Linnepe load carriers are compatible with the removable towbar from Linnepe. All you have to do is dismantle the ball head to install the load carrier.
If you would like to use the trailer hitch, the Linnepe load carrier can be dismantled in a very short time without tools using quick-release fasteners.
It is not possible to use the trailer hitch and load carrier at the same time.
Yes, that is possible. In conjunction with a rigid trailer hitch, the rear doors can be opened as the ball head can be adjusted accordingly. This means access to the cargo space is guaranteed even when the bike rack is installed. However, this is only possible with bike racks from certain manufacturers.
No. All trailer couplings have a nameplate with an E* number. An entry in the vehicle registration is not necessary, but possible.
As long as the trailer coupling is not entered in the vehicle registration document, the technical documents for the trailer coupling must be carried along.
Yes, installing an additional air spring is generally recommended. The chassis of many vehicles are already designed close to their load limit as standard. The trailer hitch puts additional weight on the rear axle, which further increases the load. An additional air spring effectively supports the rear axle and helps to significantly improve driving comfort and driving safety - especially when the vehicle is loaded or towing a trailer.
No. By installing a trailer hitch, it is not possible to increase the permissible payload of the rear garage. The maximum permitted payload of the rear garage is determined by the design of the vehicle and the vehicle manufacturer's specifications and remains unchanged regardless of a retrofitted hitch.
The trailer load entered in the vehicle registration document must not be exceeded. This also applies if the D value of the trailer coupling would allow a larger trailer load.