MOTORING NOTES

Waipa Post, Volume 51, Issue 3694, 6 December 1935, Page 5

MOTORING NOTES

METHOD IN MAINTENANCE. One means of cutting down repair bills and keeping the safety and efficiency of a motor car at a peak is to carry out a rather regular programme of maintenance. The following programme is recommended for cars which are driven about 500 miles a month or less. Differential and Gearbox.—The lubricant in these should be brought up to the correct level when the car is greased. The oil in the gearbox should be drained every 2000 or 3000 miles, and should be replaced with fresh oil. Sump Oil.—The oil level in the sump should be examined every time petrol is obtained, and should be adjusted if necessary by the addition of oil of the grade recommended by the maker of the car. The sump should be drained and refilled about every 1000 miles.

Tyres.—The air pressure in the tyres should be adjusted weekly. At the same time it is advisable to inspect the tyres and remove any small pieces of stone, iron or glass which may have become embedded in the tread. Any fractures in the cover should be vulcanised to prevent water from rotting the cord casing and causing a blow-out. Generator and Magneto.—One or two drops of light oil should be put into the lubricating holes each month.

Brakes. —If the brake pedal can be made to touch the floorboard the brake rods should be adjusted, and if no more adjustment is possible it may be necessary to have them relined. In the case of hydraulic brakes the oil reservoir should be examined at least once a month, and filled up with special brake oil if necessary.

Electric Wiring.—This should be examined every few months for fray- ' ed or broken insulation.

Chassis.—An inspection of the chassis should be made occasionally, and any loose nuts and screws should be tightened.

A MOTOR DANGER. One of the greatest dangers of motoring the world over is a purely inherent personal factor known as the lag, or lapse, that is inevitable between the observation and the act of operating the controls, says a safety first message of the Automobile Association (Canterbury). This phenomenon is altogether outside the scope of the engineer. It is a retarded muscular function with which the physician alone can deal. Just how serious a bearing time lag has on motoring safety may be gathered from the recital of a few facts, the results of exhaustive tests overseas. It was found that the lag varied considerably between car drivers selected at random, from threefifths of a second in the case of a number of taxi-drivers, up to two seconds for another class who might have been expected to react much more quickly. Others again failed to respond to the expected signal, even after repeated trials. The general outcome of the tests indicated that a lag of three-fifths of a second was the minimum, and one and one-fifth of a second a fair average for a considerable number of keen and experienced men. The significance of these very short intervals of time is not appar-

ent until their effect is realised in actual braking* performances. As an V example let it be assumed that the driver of a car running at 40 miles an hour is required to apply the brakes with -maximum force when a selected spot is reached, and not before. His lag is three-fifths of a second, with braking efficiency 75 per cent. The car will cover 106 ft. from the selected place before it

stops. Another driver with one second and one-fifth lag repeats the performance with the same car, but time it will travel through 141 ft and will be running at 28 miles an hour when it passes the spot at where the first man stopped. If the car weighed one ton it would have a striking force of about 29 tons at this point. In result, instead of an actual braking efficiency of 75 per cent., the corresponding efficiencies would be reduced to 50 per cent, in the first case and to 38 per cent, in the sec* ond—very Substantial differences. If by any means the lag period could be reduced to no more than three-fifths of a second all round, it may be taken for granted that accidents would be reduced substantially in number, and also the extent of personal injuries and damages to vehicles and other property.

WASHING A CAR. REAL SECRET OF CLEANING. The real secret of cleaning down a mud-bespattered car is to use plenty of water. Hose freely with a gentle flow on the body panels to soften out the mud deposit, but use a stronger jet under the wings and on the chassis, where the finish is of not such a delicate nature. When liberally soaked, a sponge well loaded with

water should be used to remove the softened mud.

This completed, squeeze out the sponge and squeeze it almost dry. Then go over the panels to remove the excess water. Follow this by leathering it down with a damp chamois, then finally clean it up with a practically dry leather. This should give a very good finish. For this purpose the chamois should be soaked well, then wrung out and applied to the panels with regular and fairly firm strokes.

Then, if it is desired, a final polish can be given by using one of the various well-known preparations which are now on the market. There is much to be said for hosing down at the conclusion of a journey, when the mud on the ear is still wet. It will need less water, and less energy to remove entirely. There are also various types of brush which can be used for the underside of the wings, the spokes, and the inaccessible parts of the chassis, but do not, in any circumstances, use a coarse brush for- the bodywork. Any chamois leather used for the bodywork panels should be kept for this purpose alone, as if employed on the chassis and other parts it may become contaminated with grease, making it difficult to get a good finish for its rightful purpose.