Transmission & Final Drive
D9531 has a Hydraulic, three-speed Voith L217u transmission unit which transfers power from the engine via a final drive to the wheelset. The transmission and final drive were sound but metalastic mountings have been replaced and the auxiliary drive coupling rubbers replaced as well as thorough strip and repaint.

Modifications were necessary to the Reverser and Tooth-on-Tooth as the originals were worn out and replacement parts scarce. A larger reverser piston and new Tooth-on-Tooth have been installed and spares purchased for the future. Transmission and final drive oils have been completely drained and refilled with new.

Brake Frame and Associated Equipment
At the time of dismantling D9531 was Vacuum brake only but has been rebuilt as dual (Air & Vacuum) braked which will make it a far more versatile loco. The control systems for this have been designed in-house from scratch as no 'standard' Class 14 air equipment exists and will require certification prior to acceptance for traffic.

A refurbished Westinghouse air generator (Ex-Class 37) has been fitted and new framework designed - the original would not have been able to produce enough air for the dual brakes (air & vacuum) now being installed.

The brake frame is the original. It was stripped and repainted and had some extra cross pieces welded into it to accommodate the extra equipment required for dual brake control.

Some original items remain on the brake frame but many additional components have been added from different sources, all parts new or old have been tested and refurbished before installation.

The air system was run up under the locomotive's own power for the first time on the 16th of October 2011. 120 PSI air pressure and full brake cylinder pressure were acheived with just a few minor leaks.

Auxiliary Equipment, Air Tanks & Frames etc
The original 110V DC auxiliary generator has been refurbished and refitted. This is driven from the transmission and sits directly under the brake frame.

Two large compressed air tanks are required for the main air reservoir, these are ex-Class 86 electric. Extra framework was required to accomodate them in the nose roof space, above the transmission. A contractor designed an underslung frame enabling the extra weight to be spread evenly. Originally this was to be welded into the nose roof, but has been welded across the main sideframes with extra bracing.

Originally two small air tanks, sat on top of the brake frame, provided all the air the loco required. This space now accommodates a single auxiliary air tank, an air timing tank and the main air control panel.

All components, frames, pipes, conduits etc have been cleaned, painted and refitted (old paintwork removed, bare metal exposed, primed, undercoated and glossed) and new solutions built in as required.