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).
Seizing issues and the design of the Spectre Gearbox compared to standard models.
| Identifier | ExFiles\Box 94\1\ scan0165 | |
| Date | 10th August 1935 | |
| To: [redacted] From HDY.{William Hardy} SECRET. c.c. [redacted] x328 GRY{Shadwell Grylls} SpectreCodename for Phantom III Gearbox. With reference to the seizing of the bushes of the constant mesh gears, and the spigot bearing of the box on S.S.1. in France, we are not sure whether it is generally understood that as far as the design is concerned there is no difference between the SpectreCodename for Phantom III box and our standard boxes regarding the lubrication or general proportions of these bushes. Seizing was experienced on the first synchromesh boxes made in 1931, but was overcome by the use of floating bushes and the oil holes and grooves now used. We have never heard of a complaint of seizing or wear on a production car since the above modifications were made, and on enquiry of the Repair Department we are told that they know of no case amongst the whole of the synchromesh cars that we have made. Consequently when designing the SpectreCodename for Phantom III box we had no reason to suppose that the standard scheme would not do, as the rotational speeds are no higher than on the Bentley, and the pieces are very little larger. However, the testing in France has shown that improved lubrication is necessary on this box, and we are accordingly preparing a scheme. Some increase of cost and weight will be unavoidable. The general design of the SpectreCodename for Phantom III box is almost exactly the same as for the present standard Phantom 2 box, with synchronised second speed, such differences as there are being due to the provision of a helical 1st and reverse. The size is, however, considerably less as the shaft centres are 4.5" and 3.75", and the weights 197 lbs and 134 lbs (without clutch casing but with servo and change gear bracket in both cases), making a saving of 63 lbs or 32%. HDY.{William Hardy} | ||