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).
Performance and development of the synchro-mesh gearbox.
| Identifier | ExFiles\Box 15\5\ Scan286 | |
| Date | 7th May 1932 | |
| X7 310. XS-310. To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to S. Da.{Bernard Day - Chassis Design} c. to Ey. SYNCHRO-MESH GEARBOX. On the 25 HP. the synchro-mesh part works very much better than any other car we have tried which has had synchro-mesh change. The results we have obtained are far superior to those on the american cars. This means that we have set ourselves a very high standard, and when we come to the Phantom ll we have not yet so far completed been able to get equal results to the 25 HP. It looks as though the best compromise is the thinner and reduced amount of oil in the gearbox, less steep angle on the cam, and perhaps stronger plunger springs. As regards the gears working out, E's modification appears so far - on three cars that have been tried - to provide a complete cure. We are rather concerned, however, by Hancock's report that 19-SK. car is working out of top as well as third because the arrangement for taking the top gear drive is the best we know of and is the same as we are using on the 25 HP. and which on there has never given any trouble. The problem of keeping the direct drive clutches into engagement is one which they have not solved in U.S.A. They still have trouble on this. Hs.{Lord Ernest Hives - Chair} | ||