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).
Secret memo detailing the first test of a reverse torsionally free pinion in an India 4-speed gearbox.
| Identifier | ExFiles\Box 6\4\ 04-page076 | |
| Date | 23th February 1925 | |
| To Mr. [obscured] from AJS. c.c. to [obscured] c.c. to SY. c. to HS.{Lord Ernest Hives - Chair} c.c. to [obscured] c.c. to [obscured] Y5310 SECRET. AJS1/IB.23.2.25. INDIA - 4 SPEED GEAR BOX. We wired R.{Sir Henry Royce} last night about 12.30, as follows:- "FIRST TEST OF REVERSE TORSIONALLY FREE PINIONS "AS PER YOUR TELEGRAM APPEARS TO PROVE THAT SCHEME PERFECT "BUT REQUIRES ANOTHER TO CONVINCE THAT BAD TOOTH BEDDING NOT "NOW DUE TO LESS STIFF SHAFT DEFLECTION WE THINK ANOTHER "REASON. IF SECOND TEST SATISFACTORY MAY I RETURN WITTERING". This first test was made for half an hour at full torque. The full faced forks were used with .007 total clearance axially, but no spring plungers were fitted. The gear for most of the time showed no tendency whatever to come out, but for a short interval did require 3 lbs. to hold it. The bedding of the teeth was not all that could be desired, but we think this was due to reasons not affected by the present experiment, and the very small amount of end pressure which was registered for the interval referred to, we think might be accounted for by the following facts:- 1. In the previous experiment the reverse was pushed out with such force as to shear the key in the change speed lever and shaft. This allowed the lever to get out of timing with the pendulum lever, so that the gears, although appearing to mesh perfectly when assembled in the box, did not do so after the car had been | ||