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).
Test notes and data tables on rear gearbox clutch effort at various speeds.
| Identifier | ExFiles\Box 94\2\ scan0230 | |
| Date | 11th May 1937 guessed | |
| File please Pg Rear box 328 We have measured the effort to free up a stationary clutch plate at various speeds in Top and 2nd Gear on 33G7. Effort measured was the minimum which will eventually drag the gear regardless of the time taken. Conditions { Top gear cone 9° 2nd " " 5 1/2 increased travel MSAL 4951 } [Table 1: Normal oil level] Speed | Top | Effort (lbs) 2nd 5 | | 9 10 | 11 | 15 | | 8 1/2 25 | | 9 30 | 11 | 50 | 10 | [Table 2: No oil] Speed | Top | Effort 2nd 5 | | 8 10 | 10 | 15 | | 9 25 | | 8 30 | 10 | 50 | 9 | | ||