THE GEAR-SHIFTING BUGABOO
Probably the chief bugaboo of the new owner is gear shifting. This
is evident from the fact that the average motor-driving novice will
leave the gear in high when the car is slowed down practically to a
standstill, and make the engine labor in order to pick up speed again,
rather than run the risk of making a noisy shift. He has learned from
his brief experience that, in addition to the noise he creates, he does
not mesh the gears anyway, and has to start off from a standstill.
Consequently he does not shift gears, but makes the engine start on
high-speed gear.
This, no doubt, is the cause in a large measure of the great popularity
of six-, eight-, and twelve-cylinder engines, since with motors of this
type the gear shift is not so necessary. There is a greater range of
speed; a greater flexibility and power may be delivered at lower speed.
Even the manufacturers of four-cylinder engines have designed their
motors for higher speed with greater gear reduction, which makes it
easier for the engine to pick up the load from the very lowest speed,
consequently making the car more popular with the prospective owner.
Inventors are continually at work trying to devise simple methods of
bringing about an adjustment of load to speed without actually sliding
the gears into mesh, and one very popular type of car is arranged so
that no sliding of gears is necessary, and another one or two leave out
the gears entirely.
However, the three-speed sliding-gear transmission seems to be the
most satisfactory, considered from all standpoints, including cost of
manufacture, ease of repair and care required, consequently the owner
should learn at once how to manipulate the gear lever with a minimum of
noise, which is largely a matter of practice.
If a man should get into a strange car he could hardly be expected to
shift the gears noiselessly under all conditions; but a man who owns a
car and drives it should very quickly learn the peculiarities of that
particular car and be able to make the required gear shifts with ease
and confidence.
[Illustration: CYLINDER OF STEEL, AND THE GEAR WHEEL WHICH WAS HAMMERED
FROM IT]
Shifting gears at the proper time saves racking the entire mechanism
of the car. It usually is not very difficult in the average car to
shift to a higher gear, although some car owners manage to stir up
considerable noise in doing this. One of the sources of trouble in
this respect is a dragging clutch. But most cars now are equipped with
a clutch brake, and by depressing the pedal far enough this brake is
brought into play and overcomes the tendency to drag.
Usually the best results can be obtained in shifting from first to
second gear by speeding the car up a very little on first, shifting
out of first and hesitating an instant in neutral and then shifting
into second. Unless the clutch-brake action is harsh the clutch pedal
should be depressed all the way in making this shift. The procedure is
the same in shifting from second to third. Care should be exercised,
however, not to speed the car up too much before shifting, and the
throttle should be in closed position and the accelerator pedal
released during the time of the shift.
Changing from high to a lower gear is where the most of the trouble is
experienced and this is usually due to the fact that the car is being
driven at perhaps twenty-five to thirty miles an hour and the driver
for some reason or other thinks he is going to have use for the second
speed. Immediately he proceeds to shift; the result is audible for
half a mile. Usually no difficulty would be experienced in shifting to
a lower gear if the car speed is diminished sufficiently. As a general
rule, when shifting to a lower gear the speed of the car should be a
little less than when shifting to a higher, between the same relative
gears.
In ordinary driving the gear need not be shifted to first speed except
when the car is brought to a standstill and on a level road the
second-speed gear need not be employed until a speed as low as five to
ten miles an hour is reached. The gear should be shifted when the car
speed has been decreased to this extent, and the driver should guard
against shifting before slowing down simply because his judgment tells
him he is going to have to use a lower gear, if he desires to make a
silent shift. There is a tendency to anticipate the necessity and then
to do it immediately and before it is required; the consequence is
noise.
When climbing steep hills it is desirable to make the shift at a little
higher car speed than on the level, otherwise the car may lose so much
momentum during the operation that the engine will be unable to pick
up the load and will stall. This is a rather difficult situation which
needs special handling.
In a great many cases a silent shift may be made on a hill by leaving
the throttle slightly open so that the engine speed will increase when
the clutch is released and make a very quick shift with the clutch but
partly released.
After the driver becomes a little experienced he may shift from third
to second without sound at practically any car speed that the engine
is able to deliver on second gear. This may even be found of value
when climbing steep hills and in anticipating necessary shifts. To
make this shift at high speed, release the clutch, shift gear lever to
neutral notch, engage clutch, and accelerate engine speed to a point
which experience tells you is the correct engine speed for second gear
at that car speed, disengage clutch and shift into second. This is a
matter for experiment and experience.
In starting the car grinding of the gears occurs because the owner has
not patience to wait the five seconds that may be necessary for the
clutch to stop spinning before meshing the gears.
Another source of annoyance which often leads up to a noisy gear
change, comes from the fact that occasionally it is not possible to
bring the first-speed gears into mesh when about to start the car.
This is due to the fact that the gear teeth line up so that the gears
cannot be slid into mesh. This may be overcome by leaving the lever
in neutral, engaging the clutch so that one gear will spin, and then
disengage the clutch again before shifting the lever. It may need one
or two repetitions of this before accomplishing the desired result, but
a little patience will save strain on the gear and a minimum of noise
in shifting.
A noiseless shift cannot be made from first to reverse or reverse to
first unless the car is at a standstill.