Coupling a trailer correctly
Basics and step-by-step instructions
Basics
The height of the towbar
When coupling a trailer it is important to take account of the height of the towbar!
It is frequently the case that the height of the towbar on the towing vehicle is significantly different from the specified range. This is especially the case for vehicles (e.g. off-road vehicles) with long travel suspension. It may be possible to fit spacers between the trailer coupling and the drawbar to adjust the towing height or fit a height adjustable coupling to the towing vehicle.
Any modification should only be carried out by a professional workshop.
Towbar couplings for trailers are built to DIN 74058 or ISO 1103 with a height of 430 ± 35 mm. This means that the height of the towbar ball on the car must be in the range 395 to 465 mm.
Horizontal swivel range
The towbar ball must be freely exposed in any case and ensure a horizontal swivel range of 20° to the left and right.
Vertical swivel range
The towbar ball must ensure a vertical swivel range of 25° up and down.
Caution – trailers standing at an angle
Trailers which do not stand level, due to difference in the coupling height, show increased wear of the ball as well as the coupling.
- The necessary swivel range is restricted.
- The trailer can more easily become detached.
- The road handling is impaired and there is an increased risk of the trailer weaving.
- The braking performance is worse.
Coupling step by step
Unbraked trailers
Unbraked trailers (up to 750 kg) are equipped with a safety cable that prevents the trailer coming loose in the event of unhooking.
Firstly, remove the wheel chocks from the trailer and push them into the holder on the trailer until they engage.
Before driving off, make absolutely sure that the ball coupling is not worn or dirty.
Pull the handle of the ball coupling until fully raised.
Place the ball coupling on the ball head of the towing vehicle while simultaneously looping the safety cable around the neck of the ball.
If the drawbar load is sufficient, the ball coupling will engage automatically. Otherwise, press the ball head coupling down by hand until it engages.
Make sure that the safety indicator is in the green / positive range. To ensure safety, attempt to lift the coupling off.
Connect the plug to the towing vehicle to establish the electrical connection. And make sure that the lighting system is working correctly.
Test the rear lights, load up, and you’re ready to go.
Braked trailers
Braked trailers (751 kg to 3500 kg) are equipped with a breakaway cable that starts an automatic braking process if the trailer becomes unhooked.
Firstly, remove the wheel chocks from the trailer and push them into the holder on the trailer until they engage.
Release the hand brake.
Before driving off, make absolutely sure that the ball coupling is not worn or dirty.
Place the ball coupling on the ball head of the towing vehicle by cranking the jockey wheel down to the appropriate height.
If the drawbar load is sufficient, the ball coupling will engage automatically. Otherwise, press the ball head coupling down by hand until it engages.
Make sure that the safety indicator is in the green / positive range.
To ensure safety, attempt to lift the coupling off.
Crank the jockey wheel all the way up and turn the toggle handle to raise the cylinder unit. Then turn the toggle handle firmly. Please note that it is not necessary to raise and lower the cylinder unit with an automatic jockey wheel. An automatic jockey wheel unit has a wheel that can automatically be folded in or out.
Attach the breakaway cable to the point provided on the trailer coupling. If your trailer coupling does not have an attachment point, you can attach a clamp to the ball neck of your trailer coupling. Clamps are available as accessories for our trailers. Your dealer will be happy to advise you and recommend the right clamp for your trailer.
Connect the plug to the towing vehicle to establish the electrical connection. And make sure that the lighting system is working correctly.
Please observe country-specific regulations. The video refers to the legal situation in Germany. In Switzerland and the Netherlands, different fastening rules apply to the breakaway cable. Detailed regulations can be found in your manual.