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C.24
THE
AUTOMATIC gear shift
Many test applicants show up and undertake the practical driving exam in an automatic
vehicle. This is not surprising - a pass is easier to achieve and, in some
countries
it is legal to drive automatic and manual
vehicles afterwards. However, many motorists don't fully understand
automatic transmissions. Here are some basic principles, which must be
understood, before driving a vehicle with automatic gear-change:
| P
R
N
D
2
1 |
 |
What
are
they
all
about? |
| P
- Park |
A
locking mechanism stops transmission from turning. P engaged on a
slope will stop the vehicle from rolling away unexpectedly. Caution:
Only engage P after the vehicle has stopped completely and
the handbrake has been applied! (Major damage may occur
otherwise). |
| R
- Reverse |
Engine
will not start when gear shift is in R position (or D, L, 1,
2). Always look behind when R is engaged and the vehicle is in
motion! |
| N
- Neutral |
There
is not locking mechanism of the transmission. If none of the brakes
(footbrake or handbrake) is applied, the vehicle may roll, just
like a pram, which is let go! Engine will start in N. |
| D
- Drive |
Standard
position when driving. Engine will not start when gear in D
position. (Always check this first before calling for road
service!) |
| 2
- Second gear |
Yes,
automatic vehicle do have gears. This gear is mainly used for
driving uphill or downhill - depending on the gradient and the
speed. (Read article below). Engine will not start when in 2, 1
or L position! |
| 1
(or L) First gear |
Same
function as 2, at a lower speed. (Please note - there are many
varieties in automatic gear shifts. Here is a basis model
only. |
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An
automatic vehicle can stall - in cold weather or when the
engine is giving trouble, etc. It's vitally important in an emergency
situation that new drivers know to engage neutral, or the engine will
NOT restart! |
Some motorists don't understand
gears 2 and 1 (or L), which become very important in hilly country. Before
explaining the technical side of this, read the following story of a motorist,
who did not know the function of the lower gears in his automatic vehicle:
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The story of John, who
didn't know the dangers in automatic
Seventeen-year old John, his girlfriend Lisa and her friend Joanne were on the way home
from a birthday party. John had promised the girls that he would not drink any alcohol,
because he was driving them home that night. He had kept his promise. It was John’s first
time at the wheel with passengers, after having passed his driving test two weeks before
with a proud 92 % score.
Late that Saturday night light rain began to fall. The girls were busy chatting about
the boys at the party. John didn’t find it difficult on the well lit main road. But soon the rain
increased, reducing visibility as Joanne tried to guide him to her house in the suburbs. As
Joanne directed John to turn left, she warned him about the steep hill and a bend at the
bottom.
John's car was 20 years old, a heavy sedan with automatic transmission.
After turning off the main road the heavy mass of steel seemed to gather speed rather rapidly as it
descended the hill. It was steeper than John had expected. The girls stopped chatting.
John braked hard to compensate for the increase in speed. The bend appeared all of a
sudden, which made John brake even harder. Lisa shouted in alarm: 'Slow down John!' It
was too late. They entered the bend to fast, the tyres failed to grip the wet road,
the car skidded out of control, rolling several times after it hit an embankment.
This accident happened not through drinking or recklessness. Like many crashes it
occurred simply through lack of basic knowledge by a responsible driver. In this case
John did not know, like many people driving an automatic car, that the lower gears have
a specific, important function. |
What had gone wrong?
Increased pressure on the brakes (downhill) together with a reduction in traction (=grip
of tyres on the road) because of the rain, caused the car to run out of control.
What should John have done?
By shifting to a lower gear before the steep hill
(1, L or 2, depending on the speed required) the speed would have been kept under control
as
the engine assisted the brake.
On a wet road,
especially, there is less chance of skidding, because the brakes do not need to be
applied as hard. This same principle is vital on any slippery road in a manual or automatic
vehicle: Engage a lower gear to descend a steep hill.
Caution:
The lower gears, 2 or L, in an automatic car must only be engaged at the
appropriate speeds (check the operation manual), otherwise engine damage may occur.
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