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).
Comparison of weights between 4¼-Litre Bentley Fully Floating and Semi-Floating axles.
| Identifier | ExFiles\Box 84\4\ scan0395 | |
| Date | 10th August 1938 | |
| 202 aho 258. γ To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Cr.{Mr Cra???ster / Mr Chichester} c. DA.{Bernard Day - Chassis Design} c. Hay. Rm{William Robotham - Chief Engineer}/Cr.{Mr Cra???ster / Mr Chichester}1/MH.{M. Huckerby}10.8.38. Comparative weights 4¼-Litre Bentley Fully Floating Axle (K & M Series), and Semi- Floating Axle. Semi-Floating Axle 148 lbs. 13½ ozs. Fully Floating Axle 'K' series 118 lbs. 1½ ozs. Fully Floating Axle 'M' series 124 lbs. 5 ozs. Increased weight over 'K' series 30 lbs. 0 ozs. Increased Weight over 'M' series 24 lbs. 8½ ozs. The increase in weight on the semi-floating axle over the fully-floating axle can be accounted for as follows:- Semi-Float Full-Float M Difference. lbs. ozs. lbs. ozs. lbs. ozs. Axle Shafts (less flange on semi-float) 26 11 20 0 6 11 Flanges (semi-float axle shafts)) } 6 0 Hubs Fully-float } 13 1 -7 1 Axle tubes and Spring Pads 42 2 34 2 8 0 Centre casing 11 7 9 2 2 5 Crown wheel 8 1 6 1 2 0 Pinion 4 8 2 13 1 11 Differential casing 7 8 6 4½ 1 3½ Pinion Brgs. 2 7½ 1 12 0 11½ Hub brgs. 3 0 2 14 0 2 Other Brgs. 2 6½ 1 10½ 0 8 Bearing Housing Axle Shafts 3 0 2 0 1 0 The Foregoing Differences Account For 21 0 'K' series axle is 5 lbs. 7½ ozs. lighter than 'M' series because the axle shafts weigh 15 lbs. 2 ozs. against 20 lbs. on 'M' series, and the wheel drivers are 9½ ozs. lighter. | ||