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).
Instructions for modifications to the back axle differential casing for the Phantom III and 25/30 models.
| Identifier | ExFiles\Box 92\5\ scan0058 | |
| Date | 20th May 1938 | |
| √302 Raw GRY{Shadwell Grylls} C.c. Mr. Hs.{Lord Ernest Hives - Chair} Da.{Bernard Day - Chassis Design} RMC. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} E/HDY.{William Hardy}1/HP.20.5.38. Back Axle Differential Casing - Phantom III and 25/30. We send herewith N.Sch.4811 which shows increased radii at the corners on the inside of this casing. A minimum thickness of .150 for the wall is also required. Chamfers on the thrust washers are now necessary as shown. The conical machined surfaces on the inside must run smoothly, with a .2" radius, into the thrust faces for the differential crown wheels. E/HDY.{William Hardy} N.Sch.4811 herewith. | ||