The MGF and MG TF are fitted with three-point inertia-reel seat belts integrated with the Supplementary Restraint System (SRS) airbag package. The long-end retractor assembly incorporates a pyrotechnic pre-tensioner that fires in a collision to pull slack out of the belt before the airbag deploys, holding the occupant firmly against the seat at the critical moment. This makes the seat belt system a safety-critical SRS component rather than simply a body-in-white fitting, and the correct parts must be used to ensure the pre-tensioner, airbag and belt work together as the system was designed.
Long-End Retractor Assembly
The long-end assembly is the inertia-reel retractor mounted at the top of the B-post with the webbing running down across the occupant's body to the buckle. It incorporates the pre-tensioner cartridge and the webbing reel in a single unit. A VIN breakpoint applies: EVB102671LNF in Ash Grey fits MGF cars to VIN AD017475, and EVB000660LNF fits MGF cars from AD017476 and all MG TF cars. The two are not interchangeable, the later assembly incorporates revised pre-tensioner operation and cannot be substituted into an earlier car, nor vice versa.
The long-end assembly is supplied as a pair and a pair should always be replaced together rather than individually, to ensure matched operation on both sides of the cabin.
Short-End Stalks and Buckles
The short-end assembly is the stalk-mounted buckle that the long-end tongue engages when the belt is fastened. Multiple variants are catalogued according to VIN and market. For MGF and MG TF up to VIN 4D620548, EVB104640LNF covers the right-hand side for non-Australia-and-Japan markets, EVB104630LNF covers the right-hand side for Australia and Japan, and EVB104650LNF covers the left-hand side. From VIN 4D620549, MG TF short-end assemblies changed to EVB104631LNF (right-hand, Australia and Japan) and EVB104651LNF (left-hand).
The short-end buckle contains the receptacle electronics that signal belt engagement to the SRS control unit, which is why market-specific variants exist, different homologation requirements apply to different markets.
SRS Pre-Tensioner Safety Warning
The seat belt pre-tensioners are pyrotechnic components containing a small charge that fires in a collision to retract the belt by several centimetres. Any work on the seat belt system, including removal for access to other components, must follow the correct SRS disarming procedure: disconnect the battery and allow the SRS capacitors to discharge for the manufacturer-specified period before disturbing any airbag or pre-tensioner wiring. Used or time-expired pre-tensioner assemblies must not be fitted, a pre-tensioner has a single-shot mechanism and a unit recovered from a donor car may have been partially activated or damaged during the donor's accident history. Only matched, unused assemblies to the correct VIN specification will deliver the designed crash performance.
Ordering Considerations
The two essential pieces of information when ordering seat belt components are the car's VIN (to determine which variant applies across the MGF/TF production run) and the market specification for short-end stalks (Australia and Japan variants differ from other markets due to homologation requirements). For any belt that is showing signs of webbing damage, a buckle that fails to engage or release cleanly, or a retractor that no longer recoils properly, replacement is the only safe approach, seat belt webbing and retractor mechanisms are not repairable items. A full pair of long-end assemblies with matched short-end stalks ensures a system-level replacement rather than a mismatched repair.
Comfi-Clips, Comfort Accessory
For owners who find the inertia-reel tension uncomfortable on long journeys, particularly where the belt rubs against the neck in a low-slung sports car seating position, the M099 Comfi-Clips accessory is catalogued as a pair of small plastic clips that hold the belt slightly away from the retractor at a set tension. They retain full inertia-reel function in an emergency while removing the constant light pressure across the shoulder and neck. Comfi-Clips are a universal fitment to any inertia-reel belt and are particularly popular in sports cars where the belt run is shorter and steeper than in a saloon.