GEAR CHANGING

Southland Times, Issue 22915, 13 June 1936, Page 19

GEAR CHANGING

THE SYNCRO-MESH SYSTEM SKILL STILL NEEDED Motorists of long standing deplore the introduction of the synchromesh and other forms of easy change gearbox, on the score that they eliminate entirely the need for any skill in driving, (states the motoring editor of the N.Z. Herald). Prior to three or four years ago, changing gear called for not a little skill and judgment, and the ability to effect upward and downward changes silently and easily at any speed was the hall mark of the accomplished driver, and the man who mastered this quite difficult art looked upon himself, with some reason, as being among the elect few who really could dri-’e a car.

Now, however, motor cars are very different, and there is not one made in which even the raw novice cannot change gear silently simply by pushing the lever from one position to another. And this is as it should be, for no matter how much satisfaction a driver with real sympathy for things mechanical derives from a clean change down with one of the old type transmissions, it must not be forgotten that, after all, cars are built for the multitude, and as the mechanical aptitude of the multitude varies within very wide limits it is essential that the need for real skill in driving a car be reduced tc the lowest possible amount. Unfortunately the impression has gained ground, and it has been fostered to a certain extent by car manufacturers, that the gear lever can be slammed about from one position to another at any road speed (within the limits of the speed maxima of the lower gears) with impunity. So it can, and perfectly silent changes effected, but there is going to be put on the clutch arid the transmission as a whole a very severe strain. Motorists should never forget that the only benefit synchro-mesh has conferred is the ability to operate the gearbox independent of the road speed

and engine speed. Nevertheless, if smooth, uninterrupted progression along the road is desired it is necessary for this agreement between engine and road speed to be maintained. Before synchro-mesh was introduced, the only way silent changes of gear could be made was to so adjust the engine speed to the road speed in a ratio dictated by the gear to which the change was being made, that the appropriate pinions in the transmission would be revolving at the same speed, and thus could be meshed .together, and it followed as a matter of course that the car would proceed on its way smoothly and uninterruptedly. In a way it is unfortunate that silent changes can be made with synchro-mesh boxes whatever the relation between engine and road speed, because, although the old gear changing bogey has been scotched, mechanical troubles in the transmission, this term including clutch, gearbox, universal joints, and rear axle, have multiplied. If the engine is running too fast for the road speed as a change of gear is made, when the clutch is engaged the car will take a leap forward. If the engine is operating too slowly, it will act as a brake and impose a very sudden retarding influence on the car. In either case, the strain is taken by the parts in the transmission, and if the car is subjected to too much of this treatment sooner or later some part will fail. It will be seen therefore that although the gearbox itself is foolproof, this fact does not remove the obligation on any man who has any respect for this car to drive with skill and judgment. Though it is not necessary to go through the involved and complicated process of double declutching necessary before the introduction of synchromesh, it is desirable to attune the ear to the sound of the engine, and develop some judgment as to its speed in any gear for and given road speed, and, when changes of gear are made, to adjust the engine speed accordingly. It is not at all necessary to be very exact, but it is essential that some judgment in this respect be used, and it will be found that the car will run much more smoothly, repair bills will be lessened, and the stamp of the accomplished driver will be earned.