This section covers the drop glass and quarterlight components for the MGA coupé, the wind-down main window mechanism, the swivelling front quarterlight assembly, and the associated seals, pivots, handles, and winder hardware. The section is coupé-specific, as MGA roadsters have no wind-down glass, sidescreens replacing the fixed glass of the coupé, and all parts here relate to the coupé's unique window system. The coupé's window system is one of the most complex bodywork areas on the MGA, combining a wind-down main glass in a chrome-plated brass channel surround with a pivoting quarterlight at the front of the door for ventilation, both mechanisms wearing over decades of use and requiring specific replacement components to restore correct operation.
Quarterlight Assembly
The quarterlight, also known as the vent window, is the small swivelling window at the front of the main door aperture, mounted in a chrome or stainless-steel frame, pivoting on a vertical axis from a top and bottom pivot point and opening outward at the front to scoop fresh air into the cabin without opening the main window. The quarterlight seals, available in left and right hand, run around the perimeter of the glass, sealing against water and wind noise. The quarterlight pivot is the mechanical assembly allowing the window to swing open and closed and wears over time, causing loose or rattling operation, while the pivot pin and spring retain the quarterlight in any position between fully closed and fully open, the spring providing the resistance that holds it at an intermediate setting. Quarterlight handles are stocked in two variants for different frame specifications, and an anti-rattle washer fitted at the lower pivot point eliminates the rattling that develops as the original components wear.
A corner finisher chrome screw is stocked for the lower corner of the frame.
Window Winder & Glazing
The main window is wound up and down by a mechanical winder handle operating through the door-mounted regulator mechanism. The window winder handle is the Nuffield and BMC standardised type, shared between MGA coupés and MGB cars, and the handle escutcheon is the decorative plate that sits between the winder handle and the door casing, both being direct replacements for the factory items. Glazing rubber is the seal around the wind-down main window glass, fitted into the chrome-plated brass channel surround, with two specifications stocked to match different glass-to-frame interfaces. The outer weatherstrip runs along the waistline of the door, against which the main window glass seals when wound up, a critical wind-and-water seal that perishes with age and is worth replacing during any window system refurbishment, with window strip clips securing it to the door top rail.
Fasteners & Ordering
Recessed countersunk-head screws are used for smaller glazing and frame fixings, with UNF plain washers and nyloc self-locking nuts stocked, the nyloc specification being particularly important for the window winder and quarterlight pivot fixings where vibration loosening must be prevented. Roadsters have none of the items in this section, the relevant sidescreen and weather equipment components being covered under the Weather Equipment section. For coupé restoration, the complete quarterlight assembly covers the primary wear items, with the window winder handle and escutcheon the main wear items on the winder mechanism side. Handedness should be confirmed when ordering quarterlight seals, and the glazing rubber specification should match the channel profile of the specific door.