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).
Thread seizures on Bentley rear axles and proposals for testing modifications.
| Identifier | ExFiles\Box 84\4\ scan0213 | |
| Date | 28th May 1937 | |
| To RHC.{R. H. Coverley - Production Engineer} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} c. Mx.{John H Maddocks - Chief Proving Officer} BENTLEY REAR AXLE Examination of a number of rear axles on cars before they leave the works but which have been on dynamometer and have done a certain number of road miles shows that in several cases the acme thread has already picked up. This is a little difficult to understand as we believe the clearance round this thread is being kept very closely by a gauge to .006 - .008. On these axles on which the threads have picked up the small felt ring has almost entirely disappeared. We suggest that as a test six axles should be put through with no felt. This will show whether the felt itself, which is very difficult to fit, is the cause of the seizures. If RHC.{R. H. Coverley - Production Engineer} will let Mx.{John H Maddocks - Chief Proving Officer} know axle by axle when this modification is tried Mx.{John H Maddocks - Chief Proving Officer} may be able to say after only one or two tests if the experiment is not successful. We suggest then that a further six axles should be put through in which the felt is fitted but the annular clearance of the thread is increased to .010 - .012. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} | ||