The failure of the Wraith II No. 1 gearbox's second motion shaft during a dynamometer test.
| Identifier | ExFiles\Box 8\11\ 11-page071 | |
| Date | 3rd March 1937 | |
| To Rm. {William Robotham - Chief Engineer} from HPS {Horace Percy Smith - Experimental Factory Mgr} /RH. {R. Hollingworth} c. to E {Mr Elliott - Chief Engineer} /De. c. to E {Mr Elliott - Chief Engineer} /Hsy. c. to HPS. {Horace Percy Smith - Experimental Factory Mgr} 628. HPS {Horace Percy Smith - Experimental Factory Mgr} /RH. {R. Hollingworth} 1/CB.3.3.37. WRAITH II No. 1 GEARBOX. Failure of 2nd Motion Shaft on Dynomemeter Test. Conditions of Test. 2 hours in 1st gear. 5½ " " 2nd " 10 " " 3rd " 2 " " Top " Result. 2nd Motion Shaft GW.1198 produced in S/ZN. was fractured at the rear end, the .875 dia. threaded section breaking away completely from the shaft. There was also evidence that the inner race of ball bearing GW.869 had been revolving on shaft. The 1st and 3rd Floating Bush GW.765 in BZ/PC Etonia, which has .002 diametral clearance, was partly seized on both internal and external diameters, probably due to insufficient lubrication. It was also noticed that clutch operating trunnion, GW.766 had tightened up on gearbox front end cover GW.637. The following parts were also damaged due to rear end failure of 2nd motion shaft. GW.880 2nd Speed Outer Cone. GW.772 Servo Drive Worm. GW.460 Constant Mesh Wheel. GW.788 Ball Bearing - 1st Motion Shaft. Gearbox reassembled with new 2nd Motion Shaft, GW.1198 and new ball bearing for 1st Motion Shaft, GW.788. Oil Feed Pipe, GW.790 was replaced by Ex.26482 i.e. hole opened out from .0937 to .125 diameter to increase lubrication to floating bush. Floating bush and gearbox front end cover eased, all other parts made good and refitted. Gearbox fitted in chassis and returned to test 26.2.37. HPS {Horace Percy Smith - Experimental Factory Mgr} /RH. {R. Hollingworth} | ||
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).