The MGC automatic gearbox is a mildly modified version of the Borg-Warner Type 35 fitted to MGB automatic models, but with several MGC-specific differences. The main casing incorporates unions to feed the MGC's gearbox oil cooler, essential for managing the additional heat generated by the torque converter when transmitting the six-cylinder engine's higher torque output. The torque converter housing profile follows the C-series rear engine plate, and the torque converter itself is redesigned to match the dimensions and torque characteristics of the MGC engine. The rear clutch plate assembly is a higher-torque specification, the front servo incorporates an exhaust valve, and the governor valve body is modified for MGC performance characteristics.
The dipstick tube has a revised profile to clear the MGC engine bay.
Exchange Units and Components
Reconditioned exchange gearboxes are available on a customer's own unit basis, with the reconditioning including the torque converter. Individual torque converters are also available for separate reconditioning. The kickdown cable, which differs from the MGB's in its attachment method to match the MGC throttle linkage, is available, along with the clevis pin that connects it. The rear clutch plate kit, front servo assembly, and dipstick tube are all MGC-specific items.
Cable-to-Rod Change, Chassis Number 1299/1300
Very early automatic MGCs, up to chassis number 1299, used a cable gear change mechanism between the selector lever on the transmission tunnel and the gearbox selector shaft. From chassis number 1300, the simpler MGB-type rod change system was adopted in its entirety. The selector assembly on the tunnel is mostly the same between the two systems, with the only difference being the fulcrum pin under the selector lever, positioned on the left-hand side for cable change models and the right-hand side for rod change. Selector assemblies for both types are available, along with the cable (with trunnions, adjustment nut, lock nut, and circlips) for cable-change cars, and the rod (with ball joint, adjuster, and left-hand and right-hand thread nuts) for rod-change cars. A gearbox tunnel seal, selector-to-tunnel screws with shakeproof washers, and a carpet retainer with screws complete the installation.