When one asks the cause of a truck accident, the answer invariably comes back as the "brakes failed" or the "tyre burst". Seldom is a steering fault pointed to and yet, according to Ekhard Herrmann, general manager, passenger car division, off-road division and Ecomat O.E. for ZF of South Africa, the lack of attention paid to the maintenance of steering components is a major huge cause for concern.

"Having been involved on this side of the business for many years, I fail to comprehend that the vehicle's steering is not given the same priority as the brakes in the safety equation. The bottom line is: Just as no brakes equals an accident, so too does no steering but with probably even more dire consequences as there is no retarder or intarder to assist when the steering goes," he tells FleetWatch. 

A driver's link to the road, regulated by his perception of road conditions and resultant physical intervention, is in the form of throttle, brakes, gear change and steering. Any failure to one of these can have potentially catastrophic results.

"How many operators have considered a bus or truck ploughing out of control into a building, traffic or a crowd of innocent by-standers as being due to steering failure? Not many for as intimated, steering is the last of the driver aids is therefore 'black sheep of the family'."

"The problem," says Herrmann, "is that because of its low priority ranking, when it comes to a steering repair most operators believe it can be done in-house with a few seals or that Piet Pompies' Hydraulics down the road will suffice. 

In the accompanying photographs, ZF has provided for FleetWatch readers a number of examples of what Herrmann describes as "total neglect and ignorance in the handling of these safety critical aggregates".

Shocking. This was the condition of the steering mechanism in one of the trucks taken off the road for testing during the Centurion leg of FleetWatch's Brake & Tyre Watch initiative. We thought it was an extreme case but, according to ZF's Ekhard Herrmann, not so. There are many truckers who don't give two hoots about correct steering maintenance procedures.

The knuckle is gone - where did the vehicle go?	Angle grinding marks on a steering rack, presumably to remove a burr.

Sheared off sector shaft.	A snapped pump shaft brazed back together.

This sector (output) shaft has received an impact from the road and is about to shear (note spline deformation). How many more of these will you pass on your way home tonight?

Very few realize that a steering repair, properly done, entails a complete strip-down, crack-detection of all load bearing parts, replacement of ball sets, measuring critical parameters such as mechanical resistance of moving parts (in Ncm, not Nm!), free play, as well as a full hydraulic simulation on a test bench that checks everything from the hydraulic middle to internal and external leakage as well as setting the limiter valves to cut pressure at the correct angle at full lock. This seemingly simple rebuild also requires a multitude of special tools as well as highly trained technicians.

"What is required is an awareness among operators that not only is the steering of a vehicle an aggregate that needs regular inspection and attention but that, if neglected, can result in an accident that must not only be counted by its material cost alone, but in the cost of human lives! Now, who is the weakest link?" asks Herrmann.