MOTORDOM

Dominion, Volume 31, Issue 271, 12 August 1938, Page 15

MOTORDOM

by

Chassis

ABUSE OF THE STEERING MECHANISM

A Simple Principle Which Is Disregarded

It is laid down as an ideal principle that steering wheels shonld not be turned when a motor vehicle is stationary, but the principle is more honoured in the breach than the observance. An inspection of the order in which most cars are parked parallel with the kerb these days makes it quite obvious that if the principle mentioned were not' departed from some drivers would have to wait a very long time to get their cars out into the traffic stream again.

If drivers showed even average commonsense in so parking or leaving their vehicles that they allow enough room for each other to emerge from a space with a minimum of backing and filling the principle alluded, to would never need to be disregarded. But motorists park their cars close against each other and give the steering mechanism and the tyres a great thrashing what time they sweat and fume. They pull on the steering wheel, and they get out and swing or kick at a front wheel.

Knowing that it would bo impossible to prevent drivers from so misusing their products, manufacturers design steering systems with a sufficiently high factor of safety to. make these units proof against breakage. Proof against breakage, however, is not necessarily proof . against abnormal wear. This wear will vary with tire particular conditions, and there are occasions when the practice is very harmful. Bor an example of abuse take the case of a stationary heavy car or heavily laden vehicle with the wheels turned into the kerb. The power exerted at the steering wheel to turn the road wheels undoubtedly throws an undue strain on the steering gear and may set up the following troubles: 1. Cracking of hardened surfaces on steering box gear contacts. 2. Bent drag link, steering arms or tie rod. 3. Damaged thrust bearings in steering

box. 4. Twisted or bent steering shafts. 5. Damaged tyre walls. On the other hand, with some light cars having small section tyres, the steering wheel can be rotated without incurring any trouble other than .perhaps increasing slightly the normal wear, provided, of course, the lubricating of working parts has not been neglected. The nearer a driver keeps to the ideal practice the better it will be for the car’s mechanism, and the further he departs from such practice the more costly it will be to maintain the steering mechanism in first-class condition. Owing to the reduction of hearing surfaces employed in some modern cars, it is often advisable to use a special lubricant in the steering box in order to reduce the possibility of metal-to-metal contact and consequent friction and wear. It must be remembered that a slight “flaking” off of hard metal particles from the gear teeth, cams, levers, etc., which may not cause much actual harm to the parts, can do quite a lot of harm when carried to bearing surfaces. Should a steering arm be displaced from its correct position the toe-in is altered. Adjustment of the tie rod will correct this condition while the car is travelling straight ahead, but excessive tyre wear will occur on a curve or bend because the angle of the steering arms controls the alignment on curves.