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).
Improvements and solutions for 25 HP synchro gearbox difficulties.
| Identifier | ExFiles\Box 179\2\ img160 | |
| Date | 18th January 1932 | |
| From Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} To Ad. To Mr. c. to RV. ORIGINAL Hm{Capt. W. Hallam - Head Repairs}/Gry.{Shadwell Grylls}S/MA.18. 1. 32 25 HP. SYNCHRO GEAR GEARBOX. X5310. We have now overcome all the difficulties with this gearbox. The idling of the gears is as good as a standard production car and 3rd gear is considerably quieter this being effected by burnishing the gears. These are the original 14 DP 31º spiral angle gears. They will be ground before burnishing for production. Top gear has been prevented from working out by the new sliding piece with splines both ends to the 2nd scheme on N.Sch.3397. (except that the gears are as above.) The spigot bearing between the 1st and 3rd motion shaft is the long plain bronze bush. (Arrangement EC 7161.) The new type of reverse shaft to N.Sch.3374 has done 3 minutes full throttle running and is quite satisfactory both as regards staying in mesh and lubrication of the bushes. Both sets of oil holes in the stationary shaft are parallel and downwards 38º from the horizontal. This gearbox will therefore be fitted to the last 25 cars in 'T' series. Hs{Lord Ernest Hives - Chair}/GRY.{Shadwell Grylls} Gearbox to G.S5268 Top gear sliding piece EC.7497 3rd motion shaft. EC.7495 Pressed on sleeve EC.7496 Arrangement spigot bearing. EC.7161. | ||