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).
Comparison table of gearbox backlash test results for various models.
| Identifier | ExFiles\Box 94\1\ scan0128 | |
| Date | 21th May 1935 guessed | |
| GEAR BOX BACKLASH TESTS. AMOUNT OF SLACK MEASURED AT 1.875 RADIUS Table Data: | | VULTURE | SPECTRECodename for Phantom III 1-S-1 | SPECTRECodename for Phantom III 2-S-1 | SPECTRECodename for Phantom III 3-S-1 | BUICK | |---:|:---:|:---:|:---:|:---:|:---:| | 40/50 | J 3 SYNCHRO | ALL HELICAL | | | | | 28 EX | 2ND SPEED | I H S | | | | | CLUTCH SPLINES | .007 | .027 | .012 | .006 | .0035 | | REAR AXLE PINION | .080 | .210 | .110 | .070 | .027 | GEARBOX MEASURED AT 3RD. MOTION SHAFT | | | | | | | |---:|:---:|:---:|:---:|:---:|:---:| | TOP GEAR | .023 | .015 | .012 | .022 | .025 | | 3RD GEAR | .013 | .041 | .073 | .073 | — | | 2ND GEAR | .034 | .023 | .025 | .044 | .029 | | 1ST GEAR | | .010 | | | .082 | | ||