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).
Letter to Ferodo Ltd. regarding the trial of S.3914 clutch discs, requesting further samples and discussing oil absorption issues.
| Identifier | ExFiles\Box 141\3\ scan0219 | |
| Date | 13th October 1933 | |
| K719 Experimental Dept. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}5/KT. Oct 13th 1933. Messrs Ferodo Ltd., Sovereign Works, Chapel-en-le-Frith. For the attention of Mr.Field. Dear Sirs, We thank you for your letter of the 3rd inst. We have tried the pair of S.3914 discs and have had excellent results except for a slight squeak when cold. We did not run in the discs in any way, the output from the servo being satisfactory on the first application, remaining so when hot. Will you let us have a further dozen discs for trial in the unstapled type of servo, and also a dozen for the ordinary servo, as this material should be an improvement over RAD.13. We would ask that the undented discs have an outside dia. 4.670 - and an inside dia. 3.380 +, so that we do not have to scrape them to fit the spigots. With regard to our trouble of slipping clutches, we have analysed several more linings after use, and can always discover mineral oil. It seems almost certain that the oil mist present in the clutch pit gets into the flywheel, and is absorbed in the linings, eventually causing slip. Deliberate slipping of the clutch cures the trouble. We have soaked a lining of RAD.11 and RAD.13 in oil, and found the former absorbed twice as much oil as the latter. A clutch lined with the latter cont'd | ||