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).
Diagnostic guide for low-speed wobbles on the Phantom III model.
| Identifier | ExFiles\Box 95\1\ scan0379 | |
| Date | 29th January 1937 | |
| To Hd.{Mr Hayward/Mr Huddy} (for depot sheet). Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}11/JH.29.1.37. Phantom III Low Speed Wobbles. The most likely cause of low speed wobbles on Phantom III is insufficient friction load in the cross steering tube joints. To be free from this complaint the friction load of each joint should be not less than 3 lbs. measured at the opposite end of the cross steering tube. More than 3½ lbs. begins to become objectionable by making the steering heavy. These loads should be measured by removing the cross steering tube from the car holding the shank of the ball pin in question in the vice, and pulling with a spring balance attached to the opposite end of the tube. Neither of the two ball pads G.83415 or G.84934 should rotate in the housing. If either does rotate the friction load becomes less. The lower pad G.83415 is intended to be a tight press fit in the housing. If it is found to have been rotating this can be prevented by sweating it into position. The upper pad E.84934 is split so that it spreads outwards to grip the housing. We have not yet heard of a case of these rotating. Shims, G.84936, are available for adjusting the load of the springs to give the required friction. Rm{William Robotham - Chief Engineer}/F.J.Hardy. | ||