Grant County herald. [volume] (Lancaster, Wis.) 1850-1968, 1919-06-18
IN CLIMBING HILLS USE LOW.

Do you know just why it is neces-
sary for you to put your car into low
gear when you start to climb a steep
hill?
No doubt you have often thought it
an entirely useless procedure and
have tried to take hills on high gear
without considering just what the af-
feet would be on your motor.
If automobiles were always driven
on smooth, level roads, always at an
even rate of speed, there would be no
need of a gear case and the interest
ing operation of changing from high
to intermediate or low gear. In that
case there would be only a clutch to
connect and disconnect the engine
from the road wheels No other de-
vice would be needed to meet the con-
dition of smooth, straight roads
where speed is possible and highly
desirable. But for sandy roads and
steep grades it would be necessary to
have a very high-powered motor, and
the maximum power of such a motor
would be used only at rare intervals,
II there were no change in speed
gears.
Gasoline engines do not operate
most efficiently at low speed. To op-
crate gasoline engine with econo-
my 1t must be run at a fairly high
speed rate. On a heavy grade or a
sandy road it is power, and not
speed, that is needed. If the engine
cannot develop the power necessary
to pull the car through the sand or
up the hill while it is running at
given speed, it is obvious that it's
speed must be increased. That is the
junction Of low and intermediate
speed gears
The transmission gearset is a de-
vice which makes it possible to oper-
ate the automobile engine at normal
ly high speed to develop power and
transmit it to the road wheels at a !
lower speed. 1t is merely an arrange
ment of gears on parallel shafts
which permits selective meshing at
varying ratios, so that without de-
creasing the engine speed a lower
speed is transmitted to the drive
shaft Most people are familiar with
the principle of reducing speed by
the use of gears in other types of ma
chlnery. The gearset usually is ar
ranged for three speeds-low, inter-
mediate and high forward, and re-
verse.
The high speed gear is known as
the direct drive. which means that
the propeller shaft, leading from the
transmission case to the rear axle
is directly connected to the engine
shaft and makes the same number of
revolutions, when this gear is en-
gagged.
The intermediate speed gear prob
ably will give about two revolutions
OF the motor shaft to one of the pro-
pellor shaft, while the low speed ra-
ITO is three or three and one-half to
one. The reverse gear usually is a /
trlfie lower, or about four to one.
These figures will vary in different
makes of cars, but they are generally
accurate
Besides the transmission gear re-
duction, there is reduction at the
rear axle, through the differential
gears, ranging from three to one to
i've to one, with the average about
four and one-half to one This means
that the propeller shaft makes four
and one-half revolutions to every one
of the axle and road wheels.
The motorist who is careless about
changing gears when he starts up a
steep hill even though it seems un-
necessary, will sooner or later dis
cover that he is burning more gas
oline than is necessary.