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).
The 25/30 and Bentley clutch failing to stop, caused by excessive run-out on the clutch plate due to strain during gearbox installation.
| Identifier | ExFiles\Box 129\4\ scan0133 | |
| Date | 27th January 1938 | |
| W/K.{Mr Kilner} To Rm{William Robotham - Chief Engineer}/GuH. from Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler} 1110 c. to By.{R.W. Bailey - Chief Engineer} c. to Ex. c. to La.{L. A. Archer} c. to Hd.{Mr Hayward/Mr Huddy} c. to K.{Mr Kilner} c. to P. c. to N. Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler}3/AP.27.1.38 25/30. and Bentley Clutch. In some cases of the clutch failing to stop, we have found the plate to have a run-out of as much as .050. Since each plate is tested and passed for Production with a maximum run-out of .010, it is evident that a plate with a bad run-out must have been strained in some way, and this may have happened when fitting the gearbox to the engine, at the time when the 1st. motion shaft has entered the hub but before the spigot of the clutch casing has gone home. We fully realize that to fit the gearbox unit to an engine in a chassis or bodied car without some risk of straining the driven plate, is by no means easy, on account of the weight of the unit, and the big leverage about the splined shaft, but we do recommend that if it is thought by those assembling the unit that the hub may have been strained, it is better to dismantle the plate, test and correct the run-out, and start over again, than to risk a future complaint of the clutch not stopping and the heavy cost of dismantling. Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler} | ||