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).
Component failures and wear issues for the rear axle and springs on Goshawk-II cars.
| Identifier | ExFiles\Box 180\M1\2\ img012 | |
| Date | 7th May 1922 guessed | |
| contd:- -4- We are rebuilding them without touching them as they are still fit for service. The joints on this car do not appear to receive sufficient lubrication. We have examined the joints on 1-Goshawk-II and 2-Goshawk-II which have run 11,000 miles and 7,000 miles respectively, and these joints have been kept lubricate they have been lubricated every 1000 miles. On these cars the wear is a very small amount. On the whole we should say that the Universal Joint and Propeller shafts are very satisfactory. REAR AXLE. We have had a rear axle shaft break on 1-Goshawk-II. It broke off at the end of the serrations. The driving shaft on the other side was found to be twisted badly. We think the reason 1-Goshawk-II shafts have broken and that we have not had trouble on other cars, is due to the fact that this car has been used for Clutch experiments. We have, however, got to bear in mind that when the cars get into Customers hands, they will have less experienced drivers and use the car in hilly districts so that the life of the axle shafts must be increased. The Differential bevel wheels formed on the axle shafts have shown excessive wear on all axles which have been examined. on the early axles, we attributed it to the fact that we were running on Reinecker pinions with B & S cut wheels, but on 5-Goshawk-II which had Reinecker cut gears throughout, the wear was excessive on the bevel wheels formed on the shaft and these will have to be replaced before the car can be run again. We have instructions for trying nickel chrome pinions to mesh with the nickel chrome shaft instead of as at present, hardened pinions. There is also instructed some axle shafts in air hardened steel. The bevel thrust on 5-Goshawk-II we found the races were scored. This was the standard type of thrust bearing. We have other alternative schemes using New Departure Bearings which, so far, have not been tested severely. The spring rest fixed to the axle tube on the N.S., was loose on 5-Goshawk-II. It is possible that this was never fitted sufficiently tight as the one on the other side is perfectly alright. The tie rod under the axle was found loose on 5-Goshawk-II car, it appeared as though the aluminium axle box had rubbed away. SPRINGS & FITTINGS. We have had three top leaves break on the cars run in France. On 5-Goshawk-II the O.S. broke after 9000 miles, the N.S. was found cracked right across when the car reached Derby. The top leaf was broke on 6-Goshawk-II after 3000 miles in France. It is noticeable on the Goshawk that with the car sprung to give the correct camber at normal load, the front axle gets on to the buffers much more on this car than on the 40/50. In France the front axle is continually bumping on the buffers; even on the roads around Derby, we frequently get this happening. The suggested explanation for this is that the unsprung weight compared with the sprung weight, is more on the Goshawk than on the 40/50 H.P. This is owing to the larger wheels and tyres used. We will, at the first opportunity, give comparisons of these cars. contd:- | ||