From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Failure of a 32-EX gearbox after 5,000 miles and the subsequent inspection findings.
| Identifier | ExFiles\Box 91\3\ scan0012 | |
| Date | 11th June 1936 | |
| x300a 61-1 Hotel de France, Chateauroux, Indre. France. 11th June, 1936. GWH{George W. Hancock - Head Chateauroux}/HPH/3/JAB. To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} 32-EX Gearbox Failure. This box has now completed 5,000 miles. The change of gears has not been satisfactory. The top gear crashed The third and second were hard and lumpy. After approximately 2,000 miles, the third gear came out of mesh on the over-run (i.e. at the precise moment when there was approximately no load on the gear). The change of the top and 3rd has latterly become very difficult, jamming taking place. During the run on the 7/6/36 upon making a change from top to 3rd, the mechanism jammed completely. The top had practically come out of mesh. This necessitates the removal of the change speed mechanism by the roadside. The top selector shaft had to be prised by a bar into the neutral position. This freed the mechanism sufficiently to enable the second gear to be used, by which the car returned to the garage. The box was removed from the chassis and dismantled. The top and 3rd inner sliding barrel was found to have jammed onto its splines, but could be removed by working gently back and force till it became free. It is evident WELD / SWARF! that a stray particle of metal had entered between the splines and had caused the jam, although all the splines showed hard marks along their sides where considerable rubbing had taken place. Score marks made by particles of metal were also found on the face of the barrel itself and also inside the outer sliding yoke. There is no indication anywhere on the gears or on the shafts, of metal having broken away which could account for any metal being present in the oil, and we are forced to the conclusion that it must have been in the box during the construction, for at no time during its mileage out in France, has this box been opened in anyway whatsoever. The top gear brass cone was found to have picked up badly and had fused itself onto the steel cone. The steel cone had also become considerably discoloured due to heat, and showed deep score marks where the brass cone had been | ||