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).
Idler gear failures, brake squeaks, and bumper spring plate issues across different car models.
| Identifier | ExFiles\Box 131\3\ scan0107 | |
| Date | 18th July 1939 | |
| Ex.1/MG.18.7.39 (continued) 3. IDLER GEAR FAILURES - PHANTOM III There have been three failures to date, resulting in complete breakdown of the car. Various tests have indicated that there is a considerable variation in the mechanical strength of gears of the same type. Therefore, although we do not expect an epidemic, there are bound to be further failures of defective gears. The replacement Fabroil gear has proved to be unsuitable due to its heavy inertia, but overload breakage tests on the Attwater gear considered in relation to the satisfactory life of this material on Wraith have been very encouraging, and a supply has been ordered for dealing with complaints. The gears will be changed only in the event of failure, or when the engine front is dismantled for any other reason. BRAKE SQUEAKS - WRAITH Complaints are being received of brake squeaks, particularly on light application in traffic. Tests have been made on dissimilar linings, using a rubber base liner on the trailing shoe in conjunction with the standard Thermoid liner on the leading shoe. This combination has been run over 25,000 miles on 27.G.VI with only very slight squeaks during the last 10,000 miles. The previous linings squeaked badly after only 5,000 miles. Scoring of the drums is worse than on the previous material, but it is not abnormal for the mileage. The combination of Thermoid and Ferodo RU is now being standardised, and a Depot Sheet will be issued instructing this in cases of complaint. WILMOT BREEDEN BUMPER - BENTLEY II The spring plates have broken through the fixing holes on several cars in France, and there is a good deal of evidence that these bumpers are doing too much work without achieving a great deal of benefit. We believe that the spring plates could be made a lot stiffer without detracting from the efficiency of the bumper, and we are using Ry's car to take measurements of the deflection, and to try the effect of fitting an extra spring plate. MPR. | ||