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).
Listing 14 specific modifications required for a spare 'Spectre' gearbox.
| Identifier | ExFiles\Box 94\1\ scan0191 | |
| Date | 17th September 1935 | |
| To RHC.{R. H. Coverley - Production Engineer} X328 Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}18/KW.17.9.35. In view of the large number of experiments which we have to carry out on SpectreCodename for Phantom III gearboxes, we think it would be an advantage to have a spare gearbox so that the gearbox need only be changed over when a car comes into the shop. Will you please make as soon as possible a gearbox to the following specification :- (1) Gears to have R.R. tooth forms with pressure angle correction to N.Sch.4414. (2) Higher 1st speed to N.Sch.4326. (3) N.Sch.4320 to prevent 2nd gear jumping out of mesh. (4) Increased top and 3rd S.M. cam angle N.Sch.4605. (5) 2nd speed S.M. plunger springs G.56217. (6) Ball bearings on 1st motion shaft only to N.Sch.4537 with lengthened engine coupling shaft to suit. (7) Inspection cover N.Sch.4475. (8) N.Sch.4561 to prevent interlock pin working out. (9) N.Sch.4609. Oil drain for front bearing and plugging of 2nd motion shaft. (10) N.Sch.4592. Oil distribution and lubrication of 2nd speed bushes. (11) N.Sch.4582 and N.Sch.4583 - oil drains, etc. (12) Weight reduction of servo shaft and selecting rods, N.Sch.4494. (13) Change gear lever to suit horizontal hand brake lever N.Sch.4544. Change gear tower should be in alum. instead of steel. (14) Shortened pendulum lever in box, N.Sch.4468. | ||