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 and gear lever operational issues, including synchronisation problems and sticking cones.
| Identifier | ExFiles\Box 178\4\ img047 | |
| Date | 30th April 1922 | |
| -2- EA/Gry.{Shadwell Grylls} 15/44, 30.4.22. contd. a 500 can angle did not make the first part of the gear lever movement any easier but it became unecessary to crash the gears before the wheels had synchronised. The reason we think that the pair of cones not operating offer a drag preventing the synchronising of the other two is that with the gear lever in neutral and the back of the car jacked up, the rear wheels continue to rotate and require a couple of several lbs. ft. to stop them. We therefore arranged so that the bronze cone should have to move .15" instead of .75" before engaging. With the oil in the gearbox hot there was no drag on the back wheels and the gear changing was slightly improved. A further trouble we have just found with this box is that on coasting to rest with the gear lever in neutral the sliding piece moves partially into top gear after which the interlock prevents further movement of the gear lever. The explanation of this is we think as follows. When running in top gear the top gear dogs remain engaged. On moving the sliding piece into neutral the dogs should also return to the neutral position due to the action of the synchronism plungers in their grooves. If however the dogs seize together instead of the sliding piece being able to disengage and centralise them it will be pulled by the action of the plungers partially into top gear, since the action of these 8 springs is stronger than that of the selector springs. This is further evidence of the way that the large dial P.ll cones stick, a thing we must prevent. HS{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} | ||