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).
Modifications and specifications for the Bentley III rear axle.
| Identifier | ExFiles\Box 98\1\ scan0102 | |
| Date | 7th July 1937 | |
| SECRET. 200B 402. Copy to Mr. Dy.{F R Danby} De. Rm.{William Robotham - Chief Engineer} Mro. E/BDY.1/M.7.7.37. BENTLEY III. REAR AXLE. We send herewith Nos. 5174 and 5192 showing the axle tubes, shafts and driving pieces for this car. Various other small modifications are also shown. The tubes are of the Wraith type as made by Messrs. Tubes Ltd. For the parallel tube, from which the taper tube is made, we suggest 4" diameter by .1875 thickness. This is the same thickness as is used for the Wraith and according to our calculations will enable a greater thickness to be obtained at the hub end than for the present tube. We consider that extra metal in the tube to reduce driving tooth wear will be of most value at the hub end. The calculated weight of the new tube is 11.7 lbs against a calculated weight of 10 lbs for the standard tube. The rear track is now 58". Present Bentley 56.65". The driving piece is of the solid type recently instructed for the Wraith. The teeth on the outside of the driving piece are the same as for the Wraith, but the splines in the bore must be smaller in order to pass through the bore of the differential casing. The lower view of the hub showing the same bearing base as at present should be worked to. The die cast aluminium cap as for the Wraith is used to reduce cost. The axle tube nut is now considerably recessed relative to the smallest diameter of the teeth in the hub and to improve the accessibility, cheese headed screws are substituted for the studs and nuts at present used to secure the locking plate. This change has been found necessary on Wraith. (Cont'd) | ||