"THIS GEAR BUSINESS."

Auckland Star, Volume LXI, Issue 129, 3 June 1930, Page 15

"THIS GEAR BUSINESS."

CHANGING WITHOUT CRASH.

USEFUL DOWNHILL TACTICS.

(By AUTOSCEIBE.)

A busy inter-section about five o'clock, and traffic in one street halted. Suddenly all is clear again, and with a grinding and a grating of gears, a dozen cars leap forward. Owners of smaller cars have, perhaps, got right down to "low" to allow good acceleration, and as they shoot across the inter-section they change up with a clatter that bodes no good for the wheels in the gear box. What is done there is repeated a thousand times daily in every - nook and corner of the country, often with considerable damage to the transmission in the long run. A proper knowledge of gear changing—and it really is quite simple when practised carefully—adds tremendously to the life of the transmission. Bad gear changing, besides wearing the gear pinion wheels, makes a heavy strain on the transmission, and is one of the causes of trouble with second-hand cars. There are some cars engjned so powerfully that little gear changing is needed either on hills or in traffic, but these are so few and. far between that ability to handle the gears

should be. part of the equipment of every car driver. Needless to say, the owner of such a car pays dearly for his fiat country work, for a car that will climb steep, hills in "top" is chewing up benzine on the level going.

Simple Explanation. Surprisingly few teachers of new drivers ever give a simple and satisfactory explanation of the working of a car's gears. Without it, the new driver doesn't know why gear changes are noisy, and is poorly equipped to make the change properly. In the gear box there is a series of pinion wheels which are engaged or disengaged according to whether the car is in "top," "low" or second.- The really important fact to remember is that when you come to change gear* one pinion wheel is rotated by the-engine and the other by the back axle. . Unless these two pinion wheels are rotated at the same speed there will 'be : clashing. All that is needed for perfect changing is to so work your gear lever and your engine speed that the pinions will engage evenly. Is it as .simple as it sounds? Many drivers, remembering their own experiences, will think not, but with an hour or two of practice it can be done by anyone. There "is no' need for me to point out that the ability to change quickly from "top-" to "second" on a steep down grade may avert a collision. Most of us who. have travelled with service car drivers , have at one time or. another admired the way they handle their gears. With comparatively little practice we .can do nearly as, well.

Changing Up. When your car is stationary and you start .her off in low gear there is no trouble. You merely put in the clutch, and by letting it out gradually the car makes away without any noise in the gear box. ' When' you change from low to second, and from second to top it's often a very different story. You know that the effect of putting the car into second gear is to allow you to go more quickly, ° without running your engine any faster. That means that the engine will have to turn over more slowly, relatively to the back axle. Before you engage "second" then, you have to let the engine slow down a little.

Actually what you should do is this. You depress the clutch, at the same time speeding up the engine a little, by using !.the accelerator. Then you take your | foot off the accelerator, and bring the gear lever into neutral, holding it there for "'a fraction of a second, before putting it through to second gear position. •During the short interval in which it is held in neutral the two pinion wheels revolve at approximately the same ,speed, and engage silently. . It's as simple as it sounds, with a bit of practice. The wait in neutral probably varies a little with different makes of car, but you soon find that adjustment for yourself. The best service car driver I've ever known taught me this trick, and it always works.

Tlie same procedure is needed for changing from second to top, but the waif in neutral should be a shade longer than for the low to second change.

Changing Down. For every driver who makes a mess of changing up, there are a dozen who do so when changing down, although this too is easy, if practised. I've proved these ideas in practice by teaching some of my frieiids, and an hour's careful practice wil make you fairly proficient on the change down. You want to learn on the flat, where it is comparatively easy, and then try yourself out both uphill and downhill. Without religiously practising you will never improve at changing down.

Exactly the opposite holds good here. If you are going' uphill, and have allowed the car to labour in top, the pinion wheel driven by the engine will be going too slowly to connect neatly with that driven by the back axle. Therefore, you must speed up the engine when you move the lever into neutral. Hold it in neutral for a fraction of a second, speed up, and you will find it slips through beautifully, without the slightest noise.

Changing from top to second on a downhill grade calls for the same methods, although having to be performed with greater speed and accuracy. If difficulty is experienced at first, a good plan is to stop, or almost stop the car with the brake, speed up the engine and slip into second. Gradually you will get more confidence, until a down hill change represents no difficulty, and can be made at any speed.

New Zealand roads generally are so hilly that a fair knowledge of gear changing is essential to long wear of the car. Actually bad gear changing represents a distinct item of loss to the car owner for he can be very sure that damage is done both to the transmission, and in the gear box, and it is damage for which he will pay in the long fun, either through repairs, or heavy depreciation.