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 done on the E.50 gearbox, detailing design changes and test results.
| Identifier | ExFiles\Box 112\2\ scan0091 | |
| Date | 23th August 1938 | |
| SECRET. By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} c. Sg.{Arthur F. Sidgreaves - MD} c. Hs.{Lord Ernest Hives - Chair} c. Da.{Bernard Day - Chassis Design} c. Ba/Hdy.{William Hardy} c. RHO. c. HPS.{Horace Percy Smith - Experimental Factory Mgr} 828 Rm{William Robotham - Chief Engineer}/Gry{Shadwell Grylls}2/P.23.8.38. E.50 GEARBOX. The following is a report on the testing done so far on this gearbox. Two boxes have been made; both have been on the road in 1.B.50 car and one on the dynamometer. The departures from usual R.R. practice in the E.50 box are:- (1) Integral side shaft with no centre bearing. (2) Vauxhall type loose synchro cones. (3) 2nd speed synchromesh on 3rd motion shaft. (4) A single small reverse pinion mating with the 1st speed gears. All these changes will have resulted in a reduction in factory cost. The box weighs 8 lbs less than the 'F' Series Bentley. When the first box was assembled with 9° cones it was found that by turning the first motion shaft, holding the 3rd motion shaft still, occasional cross winding of the cones greatly increased the turning effort required. 12° cones were found to be less prone to this trouble. A preliminary run of the first box driven by an engine with 12° cones showed the drag on the 3rd motion shaft to be no greater than a 25 H.P. Vauxhall. An occasional squeal from the box was found to be due to insufficient pitch line slack of the 2nd speed gears. Next, a dynamometer run was done on the second box fitted with 9° cones. | ||