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).
The shearing of keys on the Spectre rear axle pinion during sharp acceleration tests.
| Identifier | ExFiles\Box 92\5\ scan0027 | |
| Date | 1st October 1935 | |
| X302 To Sg.{Arthur F. Sidgreaves - MD} & Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to De. c. to Dy.{F R Danby} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}10/KW.1.10.35. SpectreCodename for Phantom III Rear Axle. After making some tests which necessitated sharp acceleration on second gear, the keys on the taper of the axle pinion were found to have sheared. This trouble did not occur on the axle which has run 17,000 miles in France, because it was not subjected to this treatment. It seems quite clear that this trouble will occur in customers' hands with the existing design whenever a violent standing start is made, and therefore that some modification is required. Shearing of the keyways does not occur under normal full torque as obtained during the ordinary dynamometer test, as we have run the Vulture axle under these conditions for considerable periods without failure. Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}, | ||