Gearboxes
SE4 Gearbox
These were manufactured by Self-Changing Gears Limited, one of two types supplied by the company that was used in DMUs, the other being the R14.
This was a four-speed compound epicyclic gearbox, capable of transmitting a torque of 750 lb. ft. It was a heavier duty version of the R14.
They were used on all DMUs with mechanical transmission that had engines rated at 180hp and above:
- Class 110 BRC&W "Calder Valley" sets (180hp Rolls-Royce engines)
- Class 111 Met-Camms (180hp Rolls-Royce engines)
- Class 112 Cravens (238hp Rolls-Royce engines)
- Class 114 Derby Twins (230hp Albion engines) *
- Class 115 Derby Quads (230hp Albion engines)
- Class 123 Swindon Inter-City (230hp Albion engines)
- Class 124 Swindon Trans-Pennine (230hp Albion engines)
- Class 128 GRC&W Parcel car (230hp Albion engines)
* Most originally built with Leyland 680 engines and R14 gearboxes, there were soon re-equipped with Leyland Albions and SE4s.
One gearbox was fitted per engine, this meant that most power cars had two, the Cravens vehicles (Class 112s) had one engine per power car.