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. following a visit to their works to investigate clutch judder and the frictional characteristics of clutch facings.
| Identifier | ExFiles\Box 129\4\ scan0201 | |
| Date | 21th April 1938 | |
| 1110 Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler}4/AP. April 21st.1938 Messrs Ferodo Ltd., CHAPEL-EN-LE-FRITH. For the attention of Mr.Longley. Dear Sirs, We would like to thank you for the opportunity you extended to the writer to visit your Works, with our clutch plate known to judder, and one new one. While it was interesting to observe the unmistakable coating of steel deposited on many of the bonding wires on the flywheel-side facing of the driven plate, suggesting a partial microscopic seizure of the two metals, which certainly might contribute to deterioration in the smoothness of engagement, it is evident that there are other factors producing a definite change in the frictional characteristics of clutch facings, because the same loss of smoothness is observed (a) in the Phantom III clutch, which has cast iron faces on both sides of the driven plate, (b) with every type of facing we have tested, whether provided with any metallic bonding or not, and whether woven or die pressed. If the cause and nature of this change which appears liable to occur in practically all clutch and brake facings could be discovered, we are sure it would be a step in the right direction. Yours faithfully, FOR ROLLS-ROYCE LIMITED | ||