From 27th April 2009 towbars and their attachment to the vehicle will become part of the MOT test.
Below is a guide to all you need to know, as provided by The Vehicle and Operator Services Agency (VOSA)
Why have towbars been made MOT testable?
All European Union member states are required to have a periodic inspection regime in place for the majority of vehicle types. For private vehicles used in Great Britain, this requirement is met by the MOT test. It is mandatory for such tests to include items prescribed in the legislation, which includes towbars, as they are considered essential for road safety.
Will the check apply to all towbars?
The test will apply to any type of towbar fitted to the rear of any vehicle in Classes 3, 4, 5, & 7. It does not include towbars fitted to motorcycles as they are not covered by this legislation. Nor does it include the emergency towing eye which is fitted to the majority of modern vehicles.
If the tow ball is not fitted at the time of test, only the security of attachment of the towbar brackets and the condition of the vehicle structure will be assessed.
However, where a towbar has been deliberately rendered unfit for further use, so that the simple refitting of a ball, pin or eye is no longer possible, any remaining components will no longer be considered as a towbar for the purpose of the test.
Will fixed covers or panels be removed?No covers or panels will be removed to facilitate the inspection of any components, including tow ball covers. Components hidden behind bumper bars for instance, will be tested as far as is practicable. However, it may be necessary to inspect some components from inside the luggage compartment, including lifting of loose fitting mats or carpet.
Are Type Approval markings included in the check?
There is no requirement for the tester to check for Type Approval markings and the towbar will not be failed if they are not present.
Are the towing electrics included in the test?
The electrical wiring and socket are not part of the test. If there is an obvious fault the tester will simply advise the vehicle presenter.
What about quick release or detachable towballs?
Towbars with a quick release mechanism will be checked for excessive play between the detachable tow ball and its receiver socket. Free play in the tapered swan neck fitting of up to 3mm movement measured at the ball end is acceptable.
The check will also include that the release mechanism secures the tow ball as intended.
How will the towbar be tested?
The inspection will consist of a visual assessment of the towbar assembly for excessive corrosion, fractures and damage as well as wear of the tow ball, jaw, hook or eye. It will also include a check for the presence and security of retaining nuts, bolts, pins etc. as well as any necessary locking devices, such as split, or 'R' pins.
hecks that the towbar assembly is securely attached to the vehicle structure include that mountings, supports and fixings are of an appropriate size and type, which may involve pulling on the towbar to check for the suitability of materials used.
The condition of the vehicle structure within 30cm of all towbar mounting points will be checked for any deliberate modification, corrosion, damage, fracture or inadequate repair, which affects the strength of the structure to the extent that the security of attachment of the towbar is significantly reduced. If it is, this will result in failure.
How will wear be assessed?
Wear in a pin, jaw or hook will be regarded as excessive if the thickness of the metal at any point is reduced by more than 25% of the original thickness. Pin locating holes will be rejected if they are worn or elongated by more than 25% of their original diameter. These criteria also apply to pins and brackets for any height adjustment or swivel devices. For tow balls the amount of acceptable wear is considerably less, therefore a tow ball will be rejected if a visual assessment indicates that the tow ball is obviously excessively worn.
What about height adjustable towbars?
On height adjustable or swivelling towbars, additional checks will be necessary to check for presence, security and excessive wear of locating or swivel pins and brackets. Any locating or swivel pin retaining devices will also be checked for presence and security.
Inspection Manual Criteria
Method of Inspection
- Visually assess the towbar for wear and pull on the towbar and/or its mountings to check for security, corrosion, fractures or damage.
- Check the towbar assembly is attached to the vehicle structure using mountings, supports and fixings of an appropriate size and type
- Check the presence and security of:
a. retaining devices e.g. nuts & bolts
b. locking devices e.g. split pins, 'R' pins. Note: Some locking devices are not obvious. In such cases, the vehicle presenter should be advised of any evidence of disturbance or insecurity.
- On detachable tow balls:
a. check for play between the tow ball arm and its receiver socket
b. visually assess the condition of any quick release mechanism.
- On height adjustable or swivelling towbars, check:
a. for presence, and security of locating or swivel pins
b. locating or swivel pins and brackets for excessive play or wear
c. locating or swivel pin retaining devices for presence and security.
- Check the condition of the body and chassis in the vicinity of the towbar mountings.
Reasons for Rejection
- A towbar component insecure, fractured or excessively: •worn •corroded, or •damaged.
- Towbar assembly is attached to the vehicle structure using a mounting, support or fixing which is obviously of an inappropriate size or type
- a. retaining device missing or insecure
b. locking device missing, insecure, inadequate or damaged to the extent that its
operation is impaired.
- a. Excessive play between a detachable tow ball and its receiver socket
b. a quick release mechanism that does not secure the tow ball arm as intended.
- a. A locating or swivel pin missing or insecure
b. excessive play or wear in a locating or swivel pin or bracket
c. a locating or swivel pin retaining device missing or insecure.
- Any deliberate modification, excessive corrosion, damage, fracture or inadequate
repair of a load bearing structure or supporting panelling within 30cm of the towbar
mountings, which affects its strength to the extent that the security of attachment of
the towbar is significantly reduced
This article is meant only as a guide, and is correct at the time of publishing on 24th May 2009. You can download the Towbar MOT information as a PDF file here
Updated MOT Test for 2012
From January 2012 a big overhaul of the MOT test has been implemented. There are many new checks to be aware of, includiing trailer/caravan electrical sockets. Read all about the changes here
For more information, or if you have any questions, please visit the VOSA website or the DirectGov website