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).
Performance and wear on a gearbox, servo motor, and transmission components after extensive mileage.
| Identifier | ExFiles\Box 83\1\ scan0248 | |
| Date | 10th October 1936 guessed | |
| ( 9 ) over. Examination showed that the shaft was in good condition, and after repacking the gland no further trouble was experienced. The Klingerite washers gave no trouble, but were damaged when the joints were broken and had to be replaced by new rubber joints when the engine was dismantled at 16322 miles. GEARBOX. B.7. Gearbox. LOP GB.518. Existing, complete to above LOP incorporating:- Lec.4484 Isolated Change Speed Lever. N.S.4776 Clutch Operating mechanism. Servo Motor Mechanism LOP GB.1908 Hs.{Lord Ernest Hives - Chair}1631-1589-NS.{Norman Scott}3971. The gears remained a very good standard for silence throughout the running. The synchromesh was variable in motion. Occasionally it was impossible to engage top gear. Third gear was easily crashed, but the synchromesh worked if handled gently and given time. It became more positive in action towards the end of the mileage. The isolated change speed lever was free from rattles. The servo was inefficient when the car was taken over and excessive pedal pressure was required to obtain good braking. This gradually improved with use. The servo was examined at 10,786 miles and was found to be in bad condition. The driving fabric had bedded on the inner third of its width only and the driven fabric on the outer third. The cams were slightly slotted by the balls. The thrust races were in a very bad state. The ones attached to the arms were deeply pitted by the balls in the form of radial slots. The outer races were pitted in a similar manner but not so badly. These servo parts were fitted experimentally with a view to standardising them. The locating slots for the star springs etc., in the threaded end of the shaft were worn to a taper and the outer thrust race and star springs had picked up on the shaft. Transmission Slack Measured on rim of N.S. Rear Wheel. 1. 2. 3. 4. R.{Sir Henry Royce} 4,500 miles 3/8 3/8 7/16 7/16 7/16 16,920 miles 13/16 13/16 13/16 3/4 13/16 Increase in 12,420 miles 7/16 7/16 3/8 5/16 3/8 | ||