Secret memorandum detailing six different features of the Wraith Clutch compared to the Spectre clutch.
| Identifier | ExFiles\Box 8\1\ 01-page02 | |
| Date | 4th January 1936 | |
| GRY. {Shadwell Grylls} Does this avoid all Bentley faults? Rm {William Robotham - Chief Engineer} , No SECRET. X4709 To BY. {R.W. Bailey - Chief Engineer} from HDY. {William Hardy} HDY. {William Hardy} 1/HP.4.1.36. c. WOF. E. {Mr Elliott - Chief Engineer} H. {Arthur M. Hanbury - Head Complaints} [redacted] 612 Wraith Clutch. W. Sch.4319 herewith shows the above:- There are several features different from these of the Spectre(Codename for Phantom III) single plate clutch such as:- (1) No outboard bearing between extension in the flywheel and the casing is provided. It can, however, be fitted if definitely found to be necessary. (2) The inner shaft, on which the clutch plate is carried, is located endwise by the ball and roller bearings which support it, and the clutch shaft spider is free to slide endwise on this shaft as is done on the Phantom. (3) The thrust on the withdrawal ball bearing is equalised by yoke of the Phantom type as the efficiency of this device is much higher than for the splines besides being, we imagine, cheaper and easier to handle when assembling the clutch casing. (4) Only three operating levers are used as for the 20/25. (5) Ordinary rollers are used instead of needle rollers to carry the clutch plate shaft. (6) The overall length of the clutch is less proportionally than for the Spectre(Codename for Phantom III) as the space available between the flywheel and the cross in the frame is less. | ||
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).