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).
Experiments to resolve a 'clunking' issue in the Phantom III transmission.
| Identifier | ExFiles\Box 94\1\ scan0224 | |
| Date | 2nd November 1936 | |
| 1328 To Sg.{Arthur F. Sidgreaves - MD} from Hw/Gry.{Shadwell Grylls} c. to Wor.{Arthur Wormald - General Works Manager} c. to R.{Sir Henry Royce} c. to Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} c. to Hdy.{William Hardy} c. to Mrt. c. to MX.{John H Maddocks - Chief Proving Officer} Transmission "Clunking" - Phantom III. Attached is a list of the experiments so far carried out to overcome this trouble. So far, except in experiment (11) we have been unable to overcome the trouble on a Rolls-Royce car, but we have been unable to produce the trouble on the Buick car. The successful experiment on 30-MX{John H Maddocks - Chief Proving Officer} was a gearbox with the minimum possible backlash. Until we have discovered how to overcome clunking with a slack gearbox, production gearboxes will have to be built to these very fine limits, which are in our box as follow - Measured at 1 1/2" radius on 1st motion shaft Constant mesh pitch line .001" Top Gear .001" 3rd Gear .004" } 3rd Motion Shaft 2nd Gear .002" } stationary. Constant mesh pinion, the sideshaft C.M. and 3rd speed gear, and the 2nd speed driven gear, tight on their splines. No float in any of the 3 shafts. The lack of pitch line clearance did not make this box noisy. Hw/Gry.{Shadwell Grylls} | ||