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).
The testing and analysis of a synchromesh gearbox from an Alvis chassis.
| Identifier | ExFiles\Box 136\4\ scan0059 | |
| Date | 13th September 1933 | |
| X2061 To E.{Mr Elliott - Chief Engineer} from Ha/Gry.{Shadwell Grylls} C. Nor. C. C. By.{R.W. Bailey - Chief Engineer} Ds. C. Hy.{Tom Haldenby - Plant Engineer} Ha/Gry.{Shadwell Grylls}1/KT.13.9.33. SYNCHROMESH GEARBOXES. We have just had an opportunity of trying one of the new 2½ Litre "Speed 20" Alvis chassis fitted with synchromesh on all four gears. The car tried was a new chassis and the body an open test rig. Unfortunately it was not possible to see all the components of the box. The latter was built of two main castings split in a horizontal plane along the centre line of the 1st. and 3rd. motion shafts, the side shaft being at the bottom of the box. The constant mesh 3rd. and 2nd. gears were double helical of very coarse pitch, and 1st. gear a spur gear. The male cone was in steel with a lead-in guide exactly as in the Buick box. On the road it was found impossible to crash the gears, but 1st. gear was only engaged by colossal pressure on the gear lever, and then would frequently refuse to enter at all. This fault is said to disappear after running-in. 2nd. gear was also hard to engage, but 3rd. and top worked quite easily in spite of the short gear lever, requiring about the same effort as our 40/50. The lower gears we imagine suffer from the trouble we originally experienced on the 40/50 due to the oil drag. In our design of synchromesh 2nd. gear this will not be so owing to the synchromesh mechanism being on the layshaft. Ha/Gry.{Shadwell Grylls} | ||