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).
Repeated development of clutch 'jaggering' and 'grabbing' issues.
| Identifier | ExFiles\Box 74\2\ scan0228 | |
| Date | 12th June 1929 | |
| VL{V. Lewis / Mr Valentine}494 OY-4 June 12th, 1929. TO: Mr. Ainsworth cc - Mr. Baswell Mr. Soutter Mr. Bagnall Mr. Burton Experimental Dept. Mr. Hives (England) FROM: Mr. Olley CLUTCH - SECTION 6000 Repeated development of "jaggering" and "grabbing". This experience is well known to all of us, making necessary continual resetting of the four fingers, and in many cases continuing after the four fingers are set as perfectly as possible. On 364-FM we cut the linings right through in four places with slots 3/4" wide, well chamfered at the edges, and have now taken this down after 4000 miles. The disc shows the well known Ferodo effect of scoring the metal, but is in general better looking than any disc we have seen. The clutch, from first installing the fabrics and new disc, has been perfect and has required no resetting. These liners are to be transfered bodily with the carrying plates on to your car, 318-FM, at the first opportunity. You might let me know what you think of it after a few thousand miles. You will gather what is in the back of our minds - that the fabric liner being in a continuous ring, is too large a single block to stay flat under our extremely variable atmospheric conditions. We know that Ferodo is hygroscopic, and Mr. Nosedale tells me that although the liners are pressed and ground, and lie perfectly flat when they leave him, they are generally "bunched" a little at certain spots between rivets, due to absorption of moisture when he gets a clutch back for overhaul. This would also explain why a clutch carefully set and perfect in action at the Works, will be jerky in action a month later when the finished car is on test. -continued- | ||