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).
Gearbox modifications, hydraulic damper performance, and the rear stabiliser.
| Identifier | ExFiles\Box 11\5\ 05-page167 | |
| Date | 5th July 1934 | |
| -- 5 -- GEAR BOX. LOP. G.81283. SYNCHRO MESH 2 SPEED. The following new modifications fitted in accordance with Ms/Gry.{Shadwell Grylls} 3/EW.5.7.34 Ex. 15342 Operating Cam - 50° Ex. 15263 Mod. to G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 81164 Outer Member i.e.- Slot altered from 46° - 50°. The changing of the gears was, at the start, very lumpy and heavy to engage. By continual use and changing, it is now permissible the heaviness has decreased. The second gear can be engaged from rest without undue force and generally upon the first attempt. The changing down from third to second is still difficult to obtain. It would appear that the cones of the synchromesh stick. An easy change can always be obtained if double clutching is resorted to. Changing up from first to second presents no difficulty. There has been no failure of any mechanical units. The continuous gears were very bad for noise at the start, and did not improve until 9,000 miles had been run, after which they quickly became quiet and have remained so. The oil in the gear box is a mixture of Whitmore's and Price's Engine oil, no change having been made since the car left the works. Oil loss has been negligeable. The rubber mounting at the rear of the box has given no trouble and has not deteriorated. The rubber cushions for the torque were set up two complete turns of compression. This being found to give the best results. HYDRAULIC DAMPERS WITH CONTROL UNIT. DRAIN HOLE MODIFICATIONS MADE TO INSTRUCTIONS RECEIVED IN UNIT DRIVE. Loss of oil from the unit took place through the elbow connection on OSF. becoming loose. The steering is affected when this occurs. Unit pressure failed upon one occasion through foreign matter under the control valve. Generally, the pressure to the dampers has been maintained. A record of the pressure is as follows: MPH. MAXIMUM CONTROL. MINIMUM CONTROL. 10 24 lbs per Sq." 0 lbs per Sq." 20 25.5 " " " 0 " " " 30 27.5 " " " 1 " " " 40 29.5 " " " 3 " " " 50 32.5 " " " 7 " " " 60 35 " " " 10 " " " 70 36 " " " 14 " " " 80 37.5 " " " 16 " " " The dampers have remained free from audible knocks. Oil loss has been negligeable. The poundage has remained consistent. The anchorage of the damper to the frame has remained firm. ROLL ROD OR STABILISER TO REAR DAMPERS No.4064. This has remained intact and has restricted rolling when cornering. The springing of the car is good with maximum control at speed. With the minimum control the riding is generally good travelling | ||