Issues with synchromesh gears and the carburettor during road testing.
| Identifier | ExFiles\Box 11\4\ 04-page010 | |
| Date | 29th April 1932 | |
| To Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} From C.W.H. Hotel de France, Chateauroux(French test region), FRANCE. 29.4.32. 19-Ex. We have received your telegram and letter relating to the trouble with the synchromesh gears. We had so much trouble on the run up from Boulogne to Chateauroux(French test region) that upon arriving here I jacked the car up and watched the operation of the synchromesh, and singularly enough came to the same decision as you sent in your telegram to Le Canadel(Henry Royce's French residence). I packed the spring making it very much stronger for the plunger for the selector shaft, for 3rd and top gears, and although we have not had the trouble as previously experienced, i.e. the jamming effect, we are still in trouble with the 3rd and 4th gear coming out of mesh. Re. your letter dealing with the trouble, we are almost sure that it is not the cones that are sticking, but the sleeve temporarily seizing. We examined this very closely and on each occasion although the cones had not centralised themselves, they were clear and free from the female portion, and by getting a rod on the sleeve and easing the way in which it was binding, it immediately centralised itself. On our return journey from Le Canadel(Henry Royce's French residence) to here, we had spasms of the 3rd gear coming out of mesh, and the top gear coming out of mesh, and we could distinctly feel the binding effect of the sleeve. Apparently the dogs were engaged in either case but the sleeve had not gone forward sufficiently, consequently the dogs came out of mesh very easily. Towards the finish of the run we had no trouble so it definitely points to the binding of the sleeve. CARBURETTER. There is a feature of the carburetter which will have to be investigated, and we should like any assistance you can give us on the subject. The features are, upon braking down to slow speeds, 10, 20 m.p.h. and the action of the foot upon acceleration opens the throttle slightly more than probably is required, and then is released slightly closing the throttle slightly, we get misfires caused by shortage of petrol. This feature is very bad and the above operation is unconsciously done in most cases due to the springing or road conditions. We appear to suck all the petrol from the diffuser tube and momentarily the petrol does not flow quick enough to give us the supply. We had this happen several times whilst we were at Derby but could not definitely | ||
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).