The MGA windscreen wiper system is a Lucas-pattern installation common to many BMC sports and saloon cars of the period, a single motor mounted behind the engine driving two wheelbox assemblies through a flexible drive rack, with the wiper arms and blades fitted to the chrome-plated spindles on the scuttle. Service items include the arms, blades, wheelboxes and their seals and bezels, the motor itself (in the period-correct Lucas DR2/DR2A pattern), the carbon brushes, the rack assembly and tube kit, the mounting hardware and the small grommets and seals that complete the installation.
Original Wiper Specification
The original wiper motor was Lucas type DA48 on right-hand drive cars and DA49 on left-hand drive cars, later quoted as type DR2 on all cars (Lucas part number 75297 throughout). The motor is mounted on the left-hand side of the horizontal shelf behind the engine, under the bonnet surround shroud. From chassis 12800 (LHD, March 1956) and 13612 (RHD, April 1956), 9.5-inch chrome-plated wiper arms were fitted with 8-inch blades. The arms have a 15-degree crank and the swept area is 120 degrees.
The wipers are self-parking and are arranged to park on the driver's side of the car.
Wiper Arms and Blades
The standard pre-1971 spoon-end wiper arm and matching blade is supplied in right-hand drive (driver's-side mount) and left-hand drive (left-side mount) variants, the arm geometry differs between the two so that the blade reaches the correct sweep area on the windscreen on each drive side. The chrome-plated finish on the arm is correct for original specification; reproduction items are made to the same chromed pattern.
Wiper Wheelboxes
The wiper wheelbox is the small geared assembly that drives the wiper arm spindle. Each car has two wheelboxes, one for each wiper.
The original early-pattern wheelbox uses a rectangular five-sided retaining nut at the spindle, with the chrome-plated bezel sitting on the scuttle around the spindle. The wheelbox assemblies were changed at chassis 80384 (1600, November 1959) and Twin Cam chassis 2545, cars from this point onwards take the revised wheelbox specification. Reproduction wheelboxes, the matching bush kit, the chrome bezel, the rubber wheelbox seal and the bright five-sided retaining nut are stocked individually for service.
Drive Rack and Tube
The wiper drive rack runs in a flexible tube from the motor to each wheelbox, transferring rotational drive through a toothed flexible cable in a rigid outer tube. The rack assembly is supplied as a trim-to-fit length to suit the variation in routing across different installations, and the wiper tube kit provides the rigid outer tubing for the rack run between motor and wheelboxes.
Lucas DR2 / DR2A Wiper Motor
Reconditioned Lucas DR2 and DR2A wiper motors (without the gear assembly, which is normally retained from the original motor) are stocked, providing a like-for-like replacement for a worn or seized original. The DR2A is the later derivative of the DR2, both motors are interchangeable in the MGA installation. A carbon brush kit suitable for Lucas DR1, DR2 and DR2A motors is also stocked, allowing the original motor to be serviced rather than replaced where the brushes are the only worn item. The motor mounting kit (two kits required per car, since each motor uses a pair of mountings) and the rubber grommet that isolates the motor from the mounting bracket are supplied separately.
Polarity Note
All MGAs were originally supplied with positive-earth electrical systems. Lucas DR2 and DR2A motors are physically the same regardless of polarity, but the field and armature connections must be wired to suit the car's polarity at installation. On a positive-earth car the wiring follows the original loom; on cars converted to negative earth, the motor connections may need to be reversed for correct rotational direction. Verifying polarity before connecting a reconditioned motor avoids the wipers running in the wrong direction.
Ordering Considerations
Three points should be confirmed before ordering. First, drive side, RHD or LHD, for the wiper arms and blades, since the arm geometry differs. Second, for wheelbox renewal, whether the car is from before chassis 80384/Twin Cam 2545 (early-pattern wheelbox) or from these chassis onwards (revised wheelbox). Third, for motor work, whether a complete reconditioned motor is required or whether the existing motor can be serviced with a brush kit, mounting kit and grommets, the latter is the more economical option where the motor body itself is sound.