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).
Chart comparing gearbox and rear axle ratios for various vehicle models.
| Identifier | ExFiles\Box 136\2\ scan0309 | |
| Date | 22th June 1938 | |
| 1153 gearboxes gen. Copy. BY/CRL.{C. R. Lisson} LA{L. A. Archer}/JW.1/T.22.6.38. Will you please supply the following information required in connection with a Chart being prepared for LA.{L. A. Archer} Gear Box Ratios. Ph.III. Ph.III. (Overdrive) Wraith III. Bentley. Bentley. (Overdrive). 1st. .3342 .3696 .3226 .3628 .4199 2nd. .5031 .6900 .5027 .5784 .6693 3rd. .7596 Direct .7452 .8033 Direct Overdrive or 4th. Direct 1.2048 Direct Direct 1.1818 Rear Axle Ratio. 8/34 8/34 8/34 10/41 10/43 Reverse. .3284 .3528 .3226 .3676 .4255 Your early attention to this will be appreciated. LA{L. A. Archer}/JW. | ||