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).
Clutch failure on car 34-EX, detailing the cause and proposed solutions.
| Identifier | ExFiles\Box 96\3\ scan0089 | |
| Date | 26th May 1936 | |
| x360 To Sg.{Arthur F. Sidgreaves - MD} from Rm.{William Robotham - Chief Engineer} c. to WOr.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} c. to Gx. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}21/KW.26.5.36. Clutch Failure on 34-EX. Upon examination it was found that the clutch facing had come loose on this car. This was responsible for all the defects observed, the movement of the facing causing the flywheel to become unbalanced, which produced a marked period at 65 M.P.H. We understand that during a standing start competition with a Ford the clutch probably had some severe treatment and also the engine may have been over-revved in the lower gears. We suggest that this is the explanation as to why this clutch failed whereas we have not had trouble on our other experimental cars or on 32-EX running in France, though we have given them quite severe treatment and much high speed running. However, there is no excuse for the failure; the clutch should have withstood anything that it could get in the course of a demonstration run. The reason for the failure is that we have copied the American type of clutch facing but not their method of riveting it to the driven member, the reason being that Borg & Beck's do not yet know how to make Long centre plates. The Long lining when fitted to the Borg & Beck plate has only half the number of rivets holding it in position. We think we can double the number of rivets without difficulty, and also use moulded rivet holes with a better type of rivet. This ought to overcome the trouble, and we shall have some parts on test at the end of this week, which perhaps may mean that the driven members of not more than two dozen cars will have to be changed after leaving the Works. We must say we are not altogether happy about clutches in view of these failures and of the tendency to jagger which has appeared on 32-EX and 36-EX with use. If it were not for the objection of getting parts made in America we should recommend that all cars be made like 35-EX and fitted with Long plates bought direct from the United States. We thought that 35-EX clutch had maintained its efficiency remarkably well when we had the opportunity of trying it after its recent return from demonstration work. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||