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).
The rapid scoring of flywheels and pressure rings potentially caused by new compound cushioned clutch plates.
| Identifier | ExFiles\Box 146\1\ scan0267 | |
| Date | 1st December 1937 | |
| -2- We believe that the facings as fitted to the new type compound cushioned plates can cause rather rapid scoring (grooving or spiral grooving) of the flywheel and pressure ring and we also believe that the fitting of a compound cushioned type clutch plate is not always in certain cases a complete cure for jaggering clutches. Is it not for this reason that weaker type clutch springs have been introduced? For your information, on the 1.12.37. at 24,913 miles we fitted a G.35600 cushioned type clutch plate to 3.AZ.20. Continental Trials Car. Upon recently dismantling the engine in order to attend to the bearings, we found the flywheel and pressure rings especially the flywheel to be deeply grooved. Since the fitting of the above type clutch plate, the car had covered 7739 miles. When removing early type clutch plates in order to fit the cushioned type, we have always found the friction surface of the flywheel to be in good condition. We often find, however, that the pressure rings are out of truth, varying from .004" to .006" which makes it necessary lightly to re-grind the friction surface. Have you had cases of grooving of flywheel and pressure rings after the fitting of cushioned type clutch plates? Sr/VA. P.S. We fitted a G.84703 packing ring to the clutch. | ||