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).
Resolving engine vibration and ongoing gearbox/synchromesh issues for the 3. S. I. SPECTRE car.
| Identifier | ExFiles\Box 91\4\ scan0107 | |
| Date | 16th July 1935 | |
| HOTEL DE FRANCE, CHATEAUROUX, Indre. France. GWH{George W. Hancock - Head Chateauroux}/L/JAB. 16th July 1935. To. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} From. G.W.H. 3. S. I. SPECTRECodename for Phantom III. We completed the Car yesterday afternoon. A test run proved that the transmission vibration had been cured, by lifting up the rear of the Engine. The Engine now is much smoother. We had also cured the rattle that had developed in the timing case, by loading up the damper wheel. The load was found to have dropped to 15 lbs. slipping load. It is bad for initial sticking, a load of 20 lbs. was needed to move it. We have made the slipping load 18 lbs. GEAR BOX. The centre partition is now getting more oil on to the Synchromesh parts. The working of the Synchromesh of 3rd gear and direct, has been improved slightly. It is not however right. There is too much lumpiness with the 3rd gear Synchromesh, and too easy with the direct. The feeling is that with the third gear the cones of the Synchromesh are jamming and the sleeve tightening up, double clutching is really necessary to get this gear. Top or direct gear is just the opposite. It does not feel as if the Synchromesh cones come into operation and the sleeve moves too easily, crashing of the teeth is the result, without the change is made slowly, exactly like the Cadillac. These conditions may improve with the increased oil supply. The oil distribution in the two main compartments is still not good enough. An examination of the box under working conditions with an oil temperature of 70°C, shows that the rear compartment with its first and second gear drives situated at the bottom, picks up the oil and keeps it suspended at the top of the box. The first gear drive which is situated close to the Diaphram, is an excellent pump. It is, from our observations, pulling the oil from around the Diaphram to such an extent, that the oil from the front partition, flows into the rear through the above hole. If this gear was running in the opposite direction it would pump oil out of the rear compartment, into the centre or front compartment. Observing the front compartment,(We managed to get the lid{A. J. Lidsey} off)the two Synchromesh cones are lifting a spray of oil which upon hitting the cover, falls back on to the sleeves. | ||