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).
Diagnosing transmission groans, boominess, and roughness in a vehicle at various speeds.
| Identifier | ExFiles\Box 156\4\ scan0012 | |
| Date | 9th January 1925 | |
| S/W (Hs{Lord Ernest Hives - Chair}) copy to: S/W (EP{G. Eric Platford - Chief Quality Engineer}) X1511 CWB24/LH{Mr Haworth}9.1.25. T R A N S M I S S I O N G R O A N S. ------------------------------- Your Hs{Lord Ernest Hives - Chair}2/LG5125 received. I do not consider that the transmission groan in this car had the usual characteristics. The car in itself was rather 'boomy' and Messrs. Hooper made many alterations, and certainly gradually improved it in this respect, but did not altogether cure the trouble. Finally there was a slight boominess at all speeds, under throttle, above 12 m.p.h. and this boominess was gradually increased from 17/18 m.p.h. and then diminished from 20 to about 24; then commenced increasing again about 27 to 30, from which point it diminished to about 33. It was not possible to distinguish any accentuation of the booming at any special speed on the over-run. (and) Feeling the torque tube, the conditions were exactly the same. There was a general roughness throughout with accentuation at 20/30 m.p.h. spread over a range of 5/6 m.p.h. Both the roughness and the boominess were more accentuated at 30 m.p.h. than at 20. I have no special note as to the behaviour on third gear from which, I think, it might be assumed that there was nothing remarkable about it. When the centre joint of the torque tube was freed, barring a very slight hollow boominess in the car most noticeable when rolling over a hole in the road, the above described noises disappeared completely. CWB. ---- | ||