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).
Gearbox performance and durability tests, comparing 4-speed and 3-speed boxes.
| Identifier | ExFiles\Box 6\4\ 04-page036 | |
| Date | 27th January 1925 | |
| S.H. 403A. (500) (D.B. 173 20-9-24) J.H.D. -2- EXPERIMENTAL REPORT. Expl. No. REF. Hs{Lord Ernest Hives - Chair}1/LG27.1.25. With these modifications we have run the gearbox for 15 mins. full power maximum torque on reverse, 30 mins. full power maximum torque on 1st. speed. The gearbox is still in good condition and will be re-assembled with the original springs on the plungers on the selector rods, and will then be run full power again to see whether the gears tend to work out or whether they fail in any way. In order to make sure that we were not asking the 4-speed box to do any more than the present 3-speed box on the 20 HP., we ran a 20 HP. car fitted with a standard 3-speed box for 30 minutes full power maximum torque on reverse. The gears, bearings and forks were all in excellent condition after this test. As regards the 1st. gear, we ran for half an hour full power maximum torque. We know however from previous tests that we can run any number of hours on 1st. speed without doing any harm to the gears. As soon as we have confirmed that the 4-speed box will stand up satisfactorily, it has been agreed that we shall try again with the old original reverse shaft, with alteration to the forks only, to prove which of the modifications has given the improvement. Hs.{Lord Ernest Hives - Chair} | ||