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).
Rear axle shaft bearing failures, detailing history, causes, and arranging for examination and modifications.
| Identifier | ExFiles\Box 114\1\ scan0370 | |
| Date | 23th February 1944 | |
| 1015 To: Ev.{Ivan Evernden - coachwork} Hym. HJH. from Rm.{William Robotham - Chief Engineer} Ev{Ivan Evernden - coachwork}/Tln. c. to Wym{G. Harold Whyman - Experimental Manager}/C. Lee. REAR AXLE SHAFT BEARING FAILURES. The attached Report on [illegible] indicates the record of ball-race failures on experimental cars. As I remember the story, the first run on 8.B.5. on the Continent produced a bearing failure. The bearings were increased in dimensions and I believe altered to the self-sealing type. These have run about 75,000 miles on 12.B.5. without trouble. The bearings on the 45 mm. half-shaft, fitted to all wide track-axles are not of the self-sealing type and require lubrication by means of a grease-gun. There was some problem about keeping the grease in the bearing on 4.B.50. and an alteration to the disposition of the Belleville washer located next to the bearing was tried out on this car, and has done about 6,500 miles. Curiously enough, 3.B.50. has done 90,000 miles with a wide track and, presumably, 45 mm. half-shafts - without trouble. The bearings always fail on the off-side shaft which is the longer of the two and consequently suffers from the greater deflection to the detriment of the bearing. Summarising the evidence available, therefore, we have : 1. Recent failures are confined to chassis fitted with 8-cylinder engines. 2. They are confined to the off-side half-shaft. 3. It is difficult to say emphatically that the failures are due to shortage of lubrication because since the last bearing was fitted and failed, it is alleged that 30.G.7. was lubricated frequently. Will Hym. please arrange for the following work to be carried out : (a) Modified half-shaft removed from 4.B.50. and fitted to off-side of 30.G.7. (b) 3.B.50. off-side half-shaft dismantled for examination. (c) 12.B.50. " " Will Ev.{Ivan Evernden - coachwork} please arrange for a pictorial record to be produced of the various alternatives which have been tried on the senior Rationalised range of rear axles. We should also like recommendations for a suitable, obtainable size of self-sealing bearing to be tried out in case the modification which we are going to change over from 4.B.50. to 30.G.7. proves to be a failure. Failures of this type produce a serious service problem in our transportation and must, therefore, be cleared up. Enclosure: Enclosures/GH. 18.2.44. EW | ||