The MGB body shell has numerous apertures, pass-throughs, and panel joints that admit road noise, wind, water, and fumes into the cabin if left unaddressed. Every hole through the bulkhead, floor, and body sides was originally sealed with a grommet, blanking plug, or gasket, and on a car that has been in service for decades, many of these small but important sealing components will have perished, been disturbed during previous work, or gone missing altogether.
Services Grommet
The services grommet is the large grommet through which the main wiring harness, heater controls, and cables pass through the bulkhead from the engine bay into the cabin. It is one of the most important sealing points on the car, a split or missing grommet here allows significant noise, draught, and exhaust fume ingress directly into the footwell. The grommet is available individually or as a kit with the associated cable retainer plates.
Tunnel Grommets & Gear Lever Sealing
The gearbox dipstick grommet and gear lever grommet are available separately for 3-synchro and 4-synchro applications, the tunnel profile and aperture positions differ between the two gearbox types. The gear lever gaiter and its chrome or black bezel ring complete the tunnel sealing at the gear lever position. On 3-synchro cars, the chrome bezel ring has a distinctive elongated oval shape, changing to circular on the MkII from 1967. From the end of 1975, the ring finish changed from chrome to matt black epoxy.
Blanking Plugs & Bulkhead Grommets
Blanking plugs close off unused or redundant holes in the body, floor, and bulkhead, and are available in a range of sizes to suit the various apertures found across the production run. Individual bulkhead grommets for specific cable and pipe pass-throughs are available alongside the larger services grommet.
Battery Covers
Battery covers are available for both the twin 6-volt battery arrangement used on chrome bumper Roadsters and the single 12-volt battery fitted from the rubber bumper models. Dzus fasteners, fastener springs, and cover seals are all available to complete the installation correctly, the battery area is one of the most corrosion-prone parts of the MGB and a correctly sealed cover prevents moisture and acid vapour from reaching the surrounding bodywork.
For owners addressing road and transmission noise as part of a broader interior retrim, tailored soundproofing kits and advanced acoustic treatments are covered in the dedicated Soundproofing section.