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).
Disadvantages of the Phantom III gearbox and proposing modifications.
| Identifier | ExFiles\Box 94\2\ scan0081 | |
| Date | 23th November 1936 | |
| Sg.{Arthur F. Sidgreaves - MD} Hs.{Lord Ernest Hives - Chair} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to Hdy.{William Hardy} Rm{William Robotham - Chief Engineer}/Gry{Shadwell Grylls}/17/R.23.11.36. P.III GEARBOX. The disadvantages of the present gearbox are:- From our point of view. (1) The cost of manufacture £82. (2) Difficulty of obtaining quiet gears. (3) Tendency for gears to come out of mesh. (4) Necessity for impossibly fine limits of balance and alignment of clutch coupling and propeller shafts, to be free from vibration. From the customers' point of view. (5) Heaviness of operation of the synchromesh mechanism. (6) The best use is not made of the 4 available speeds. In our opinion the most important modification required to the present car is to make the gearbox unit construction with the engine. The immediate advantages of this will be;- (a) Freedom from vibration due to less accurate requirement of balance. (b) A quieter gearbox, and a doubtful disadvantage of a less good frame due to moving back the cross. To mount the present gearbox on the engine means moving the centre of the cross back 10". In order to achieve this the silencer must be moved back 5", and this can be done if the hand brake ropes are moved back from their present position in front of the rear axle. A 3 speed box, judging by the Packard, would be 5" shorter, which would mean very much less alteration to the chassis. It would also weigh and cost about 2/3rds of the present gearbox. | ||