Steering
Page 73
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REGULATION 79 (i) requires that the steering gear fitted to a vehicle shall be maintained in good and efficient working order and properly adjusted when it is used on a road.
Obviously, the correct maintenance of steering is of paramount importance, the safety, not only of the driver of the vehicle but of the public in general being dependent upon it. With ordinary use and correct lubrication the modern vehicle will cover large mileages before the steering requires attention but the question then arises how much wear can be tolerated.
As the Regulation requires that the steering be maintained in good and efficient working order and properly adjusted, there is no question of the prosecution having to prove that the defects present cause danger as is the case in certain other charges. Naturally if danger is caused as, for example, when worn track rod ends or king pins and bushes cause steering wobble then the prosecution's case will be strengthened.
There appears to be no case law which gives guidance as to the amount of wear which can be tolerated but the Goods Vehicle Tester's Manual {HMSO, price 6s 6c1), gives some useful information on this subject. Often it is a matter of opinion as to whether a part should be renewed—one transport engineer
will take a vehicle off the road for immediate attention while another considers a vehicle, in the same condition, suitable for several thousand more miles before docking. The Tester's Manual does lay down certain standards and although it is not law it would be a very good defence, warranting acquittal, if one could put forward in court that the amount of wear complained of was less than that stated as being permissible in the Manual.
The Manual states that it is not possible to lay down precise limits for acceptable wear at king pins but as a guide it is suggested that with the wheel braked and off the ground the amount of movement at the outer wall of the tyre should be not more than lin. for 20in. wheels and proportional amounts for wheels of different diameter.
Permissible free play on the steering wheel is given as up to one-fifth of the diameter of the wheel, i.e. 3in, on a 15in.diameter wheel, 31in. on 18in. and 4tin, on a 24in. diameter wheel.
With regard to steering linkage the following notes from the Manual are of interest. "Before assessing an item as defective because of excessive wear remember that play between moving parts is necessary if they are to function correctly. Wear should only be regarded as excessive if it is clear that the part has been considerably weakened by the wear or that joints may separate."