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).
Cause and resolution of a steering rattle on the Wraith model.
| Identifier | ExFiles\Box 9\7\ 07-page171 | |
| Date | 10th May 1938 | |
| To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} c. DA.{Bernard Day - Chassis Design} c. MX.{John H Maddocks - Chief Proving Officer} c. RHC.{R. H. Coverley - Production Engineer} Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}4/MH.{M. Huckerby}10.5.38. 650. WRAITH STEERING. A rattle occurred in the steering system of 26.G.VI during 15,000 miles test when cornering or when holding the car straight on a steep camber. It was found that the rattle was caused by the ball pads in the rear side steering tube joint clattering on their stops when the load in the steering system was just sufficient to deflect the pads to a mean position near the stops. One way of overcoming this trouble would be to increase the travel of the joint so that under normal conditions the pads were always clear of the stops. This, however, would increase the feeling of sponge in emergency conditions and the extra travel is unnecessary from the point of view of joggles. A further method tried on 27.G.VI was reversing the side steering tube so that the sprung joint was at the front end and more remote from the occupants of the car. This was an 80% cure but the noise was still just audible. We have tried on three chassis 25, 26 and 27.G.VI fitting springs wound closely so that they came choc-a-bloc at the required travel instead of the pad hitting a rigid stop. This has so far been completely successful and we suggest that it should be instructed for all production cars. The arrangement is shown on SCD.578 and involves new springs EXS.688 and ball pad guides EXS.690. Existing ball pads FW.992 will modify to the new type EXS.689. Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} | ||