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).
Page 2 of a report detailing the investigation into a clutch failure caused by a cracked cast iron pressure plate.
| Identifier | ExFiles\Box 11\3\ 03-page213 | |
| Date | 18th July 1930 guessed | |
| -2- with the tests taken which we hope will be of service to you. We have to-day sent you a telegram reading:- INVESTIGATION OF CLUTCH TROUBLE FOUND FRONT CAST IRON PRESSURE PLATE EX 5090 CRACKED RIGHT THROUGH NEW ONE REQUIRED ALSO TAPER PINS FOR OPERATING LEVERS URGENT. Having completed over 5,000 miles and completed most of the experimental tests required, we started to investigate the cause of the heaviness of the clutch disengagement. We dismantled the gear box and clutch, and found that the front cast iron pressure plate had cracked right through. This allowed this plate to expand centrifugally when the engine was revved up, causing the plate to jam on the clutch casing which caused the heaviness of disengagement reported. We had carried out the test of cutting off the oil supply, which we found made no difference. The car is now definitely held up until we can receive a new clutch plate. We enclose a sketch of the failure of this pressure plate. G.W.H. | ||