Putnam's Automobile Handbook: The Care and Management of the Modern Motor-Car

by H. Clifford Brokaw; Charles A. Starr

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.