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 examination and modifications of the S.S.I. Spectre's gearbox.
| Identifier | ExFiles\Box 91\4\ scan0115 | |
| Date | 17th July 1935 | |
| HOTEL DE FRANCE CHATEAUROUX. Indre. France. GWH{George W. Hancock - Head Chateauroux}/4/JAB. 17th July 1935. To. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} From. G.W.H. S. S. I. SPECTRECodename for Phantom III. Your Memo. Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer} 8/KW 15-7-35 received. As stated on the telephone, we started running again yesterday morning the 16th inst. Since then, we have completed 1,233 miles up to noon to-day. We have since dismantled the Gear Box to examine the floating bushes. We found the 1st to 3rd motion shaft floating bush dry, oil fumes only. The two 2nd motion shaft floating bushes well oiled and in a good condition. The modifications carried out to the last named bushes were :- The shaft was drilled, three 1.50 m/m holes equally spaced in the annulus, between the bushes. The end collar of the bushes, we filed three slots for breathing purposes. To try and lubricate the 1st to 3rd motion shaft floating bush, we have filed three slots at the end of the bush (collar end) to breath it, also drilled a 1/16" hole in the sealed pressing at the end of the 1st motion shaft nearest the coupling, for breathing purposes. The inside of the 1st motion was rusty. Examination of the 3rd and direct Synchromesh cones, shows that the 3rd gear cone was engaging hard. The direct cone had not been engaging sufficiently to keep it polished. There was a carbon deposit on it. The Fitters here say they cannot do anything to alter this state of affairs, consequently, we shall still have a lumpy third and crashing top. The trouble appears to be the inaccuracy of the vee slots in the moving sleeve. The angle for the third is apparently steeper than for the direct consequently, the plunger slips out too easily for the top gear, without the required load being applied to the Synchromesh cone. With regard to oil loss, we cannot beleive that a discrepancy between the two boxes could make one lose no oil, and ours 2 pints in a thousand miles. We can only come to one conclusion and that is the high temperature of our box, and the sustained high speed runs. | ||