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).
Specifications for the Wraith II back axle, referencing schematics 4954 and 5014.
| Identifier | ExFiles\Box 7\3\ X 602 Axle Rear-page33 | |
| Date | 1st February 1937 | |
| SECRET. GRY{Shadwell Grylls} 602. HPH BT.{Capt. J. S. Burt - Engineer} c.c.Mr.Bde. Mr. Jebb. E/HDY.{William Hardy}1/HP.1.2.37. WRAITH II BACK AXLE. We send herewith N.Sch's 4954 and 5014 in connection with the above. N.Sch.4954 shows a centre casing of R.R. type to suit the original gears with 1.625" hypoid and 8/37 ratio to N.Sch's 4831 and 4827. The largest diameter of axle shaft provided for is 1.312. This is the same size as is at present in use on the Wraith, and should be instructed for this axle also. We have reverted to our standard practice of making the differential bevel wheel solid with the axle shaft as with the oil seals on the centre casing we do not consider that it is practicable to insert an axle shaft through the seal when the axle is assembled, and, therefore, the driving piece in the hub must be detachable. A further advantage is the greater area of thrust washer for the differential bevel wheel which is secured. The pinion bearing lubrication scheme is the same as recently instructed for the Bentley on N.Sch.4985. The axle tubes are of the modified type to reduce cost and have already been instructed in the main particulars by N.Sch.4944. N.Sch.5014 shews the hub for use with N.Sch.4954. The principal differences between this and the hub previously instructed by N.Sch.4944 are that the driving piece is now a separate piece for reasons mentioned earlier, and there is now no oil seal in the hub. The lower view showing a shaft 1.312" dia. is the one required. N.Sch.4954 N.Sch.5014 herewith. E/HDY.{William Hardy} | ||