• Home
• Used vehicles
• Product news
• Dealer news
• Compliance
• Buying advice
• Archive

INSPECTING VEHICLES HOW TO IDENTIFY

FAULTS by Ron Cater,

AMInstBE SYSTEMATIC vehicle inspection is not new—for instance it has certainly been practised by some large oil companies for years. But only since the introduction of goods vehicle plating and testing has the road transport industry at large begun to take a serious interest in checking vehicle condition, and operators' licensing requirements which took effect a week ago make such inspection even more necessary.

However, in this article I do not propose to discuss the legal obligations, or which vehicle components need regular inspection; the Tester's Manual, for instance, deals very thoroughly with the latter. Although the prime reason for inspection is vehicle safety, operators' systems must also be designed on the "stitch in time" principle, to keep vehicles from failing in service, and I want to look at inspection from this point of view, and also provide some hints on how to spot trouble and identify its cause.

Contrary to what one reads in some quarters, vehicle inspection does not call for a mass of special equipment. A small crowbar (for trying spring leaves and so on) and a handlamp will do for most jobs, and what an inspector really needs is a keen eye and perhaps a little more than average common sense. Serious failures in commercial vehicles seldom occur suddenly. There are usually warning signs which point to trouble developing and if these are recognized and countered it is almost always possible to side-step the unscheduled stoppage. Often, one can depend on a good fitter working on a machine noticing tell-tale signs which eliminates the chance breakdown.

I would find it hard to count the times I have inspected vehicles which only a few hundred miles previously had been subjected to a so-called service, only to discover the odd broken spring, loose axles, brake gear seized up, steering out of track and a host of other faults. The ability to spot what others miss is based largely on a simple process of elimination regarding vehicle condition.

A vehicle's running gear will do more to ruin or enhance its performance than almost any other single section. On countless occasions vehicles are subjected to searching investigations into their power units because drivers complain about a lack of performance or the manager has sent a sharp note about a noticeable rise in fuel consumption. And yet, provided a diesel is not smoking or leaking badly it is unlikely that much can be done short of a major overhaul which will significantly increase performance or reduce fuel consumption. But realignment of loose axles, or front-end geometry, or, of course, releasing binding brakes can often have the desired effect.

Tyre condition will tell an inspector all he must know to start an investigation into alignment. "Feathering" of treads to one side or the other points to the direction in which the wheels are running out of fine. So if, for instance, the tyres on the front axle of a rigid eight-wheeler are feathered towards the offside, while those on the second axle are feathered to the nearside, there is misalignment between the two. If both tyres on one axle are feathered to the inside then the track setting is wrong, the wheels being toed-in too much. Feathering to the outside shows excessive toeing out. On rear axles, loose U-bolts and/or a broken centre-bolt will be shown up by tyres feathering-away from the loose side on a driving axle but towards the loose side on a trailing axle.

Worn king-pin assemblies show up by a definitely lumpy pattern of tyre wear, while oval brake drums will result in low patches developing in the treads.

A vehicle that shows obvious signs of being regularly kerbed not only warrants a strong word with its driver but a fairly careful check on the alignment of axles and steering gear. All these points, each one of which is a potential trouble maker, can be ascertained in far less time than it takes to read. An inspector—or fitter— needs only to walk quickly round the vehicle while running his fingers over the tyre treads. If the evidence is there, it's a safe bet that the running gear will bear closer investigation.

How does one check engine condition? Personally, I like to couple driver comments with records of consumption, plus a short run at the wheel of the vehicle. However, there is not always the time to make a short test run, and one must use other methods to evaluate engine condition. Several items point the way to the things one needs to know; most, I feel, are instantly recognizable. Whether the exhaust pipe is discharged at the side or underneath the vehicle, if fuel equipment is not doing its job properly there will be signs to reveal this. Quite often drivers will keep quiet about excessive black smoke with the mistaken idea that thereby lies more power. But the soot deposits around the end of the exhaust will give you all the information you need to warrant a check. A driver may not be keen to reveal that he has had one or two boil-ups recently, perhaps because he fears being accused of not checking water level before leaving the depot. But again the signs will be there—around the radiator cap and the overflow pipe, pointing to a loose fan-belt or leaking system.

Just as certainly the presence of numerous coats and blankets in a cab point to a thermostat not keeping the engine at a high enough temperature to provide adequate heating or for it to run well or economically. Even without records it is not difficult to see if an engine is using more than its fair share of oil. A glance at the breather while the engine is revved up will show if it is blowing by; if it is, then probably it will suck back a fair drop of lubricating oil when on the overrun.

Engine oil dripping from the clutch housing vent hole can herald main bearing failure. It is a wise precaution to check for crankshaft lift if oil is evident here in any large degree. The presence of oil over the outside of an engine should be viewed with the utmost suspicion. There must be something loose which has allowed joints to start weeping and on an engine having separate block or blocks a finger placed over the joint while the engine is under load will usually determine whether the block is loose. One of the functions that many drivers seem to avoid these days is that of keeping the engine washed down. It helps no end to pinpoint troubles in the engine room if the unit is kept clean. Provided it is hosed down regularly, only a few minutes are needed once a week to keep it so.

In this day and age oil seals are quite reliable and their failure is more often than not due to other things. Although oil seal failure is a nuisance, the occurrence should be taken as a pointer to other troubles. For instance, propeller-shaft vibration will cause loosening of differential nose-bearing carriers which in turn will lead to failure of the pinion-shaft oil-seal. So if that seal fails, accept this as a warning of troubles farther up the line—such as loose driving flanges, universal joints beginning to fail, a faulty centre bearing or perhaps a bent shaft.

There is, for course, no substitute for a short test run in a vehicle. Drivers tend to grow old with their machines and sometimes do not notice things going awry. But to the relative stranger behind the wheel many things will quickly show as needing adjustment or perhaps replacement.

For instance, a bad clutch may have grown on the regular driver but it will nevertheless play havoc with the remainder of the transmission line and sometimes the engine mountings as well. So if on your test run the clutch feels dodgy, those points should get special attention during the inspection which follows. The same applies to heavy or lumpy steering. Bad gear will throw strains not only on the steering box mountings but on the driving seat fixings as well.

Rust streaks

One has only to look at the cab doors and how well or badly they cicIse to see whether or not the structure is basically sound. Dropped doors often herald a failing structure or at least faulty cab mountings.

Telltale rust streaks around wheel nuts should trigger off questions to the driver,

such as: -Flow often do these need tightening?" If the answer is "too often" then get the condition of the wheel discs, studs and nuts checked at the first opportunity, for a failure here is mighty expensive, most often very inconvenient and possibly dangerous. Loose carrier or chassis brackets will show up with the same tell-tale rust streaks.

On artics. damage to lead-up ramps automatically leads me to suspect the landing gear on the semi-trailer. Winding up a fully laden trailer is hard enough work even when the gear is functioning correctly, but virtually impossible if it is not. This is not always the cause, but it is worth checking. And do not overlook the simple fact that a vehicle which looks a little knocked about might be suffering from inadequate mirrors. Get up and have a look. If you can't see much through them then neither can the driver.

Do not automatically suspect that failed batteries are a result of "out of sight and out of mind". The rest of the vehicle should provide an idea of the driver's worth, and if this speaks well of him, dry batteries might point to overcharging or to their being badly situated on the vehicle. To have them mounted directly in the slipstream from the engine compartment is bad. They get hot enough through charging without being deprived of cool surroundings.

It is a good idea to relate the sort of inspection one gives a vehicle to the sort of work and routes on which it operates. For instance, a vehicle operating continuously over heavily cambered and narrow roads would, in my book, be expected to suffer quite considerably from loose axles and/or seized or binding brake gear. Why? Because its nearside wheels will constantly be subjected to traversing the bad surfaces of gutters. And. because of the heavy cambers, in had weather the gutters will be streaming with road dirt, and water which will be splashed over the undersides of the vehicle almost continuously.

Conversely a machine that dashes 300 miles a day up motorways would come in for rather different treatment. Whereas the conditions mentioned earlier will call for frequent brake application (which will tend to cause foreign matter to work its way into the various bearings in the braking system, so that they seize in a binding condition) on a motorway the machine might travel for up to three hours without the brakes being applied at all and it is not unknown for systems to simply seize in the off position. So while in one case we are looking for a reason why the vehicle will not go very well, in the second instance we need to check how quickly it can be stopped.

Rates of wear A machine working in heavily congested or very hilly conditions where the frequency of gear-changing is high would obviously need particular attention to the change-speed mechanism and its mountings. I am not suggestin,g that the rest of a machine can be ignored excepting for the one particularly relevant area, but rather that one must try to visualize in which components the highest rate of wear and tear is likely.

An inspector regularly looking at a fleet will soon get to know the lonahs, those machines that are never right no matter how many adjustments are made, and he will also soon learn to recognize when the complaints are or are not valid. He should quickly see the worth of appreciating drivers' problems. For instance, a driver complains that the vehicle he drives has heavy steering. It is no earthly use telling him that so and so has driven it for months without complaint unless you can prove that there is nothing extraordinary about it.

One must, of course, take account of the work the complaining driver is doing with the machine. Again, one must recognize that the round trip from London to Birmingham up MI every day is a very different matter from deliveries around the villages of the West Country.

Fleet inspection is probably the most indirectly remunerative operation that any operator can initiate. The man who does the job can develop an almost uncanny nose for problems once he knows the fleet intimately, and very soon more than pays for his keep in saved expenditure.

To do his job well, however, he must learn every trick of the trade, a few of which I have tried to highlight here.

pOLLIJTION is a subject with many facets. While the Minister of Transport has been providing r a forum for complaints about diesel smoke, lorry noise and other undesirable manifestations of the machine age, he has also been giving what appears to be unlimited freedom for the French to send their refuse and sewage into the UK.

This is just one of the many fascinating discoveries that can be dug out of the Goods Vehicles (Operators' Licences) (Temporary Use in Great Britain) Regulations 1970. The intention is to bring within the new licensing system foreign vehicles coming into the UK on roll-on roll-off services.

Basically the operator should have an operator's licence and a limited carrier's licence if the vehicle has an unladen weight of more than five tons. Where there is a quota agreement the operator's licence is replaced by the bilateral permit and for some items of traffic from some countries not even the permit is required. "Refuse and sewage" from France is an example.

In fairness it must be remembered that quota agreements are reciprocal. British refuse and sewage can be sent to France with equal freedom. The agreement opens up a prospect during European Conservation Year of each country furiously exporting its rubbish and pollution across the Channel and in each case recording the results as a remarkable achievement in cleanliness and purity.

The regulations provide evidence that bilateral arrangements have already been made with Austria, France, Western Germany, Italy, the Netherlands, Rumania, Sweden and Yugoslavia. Presumably amendments will be published as further agreements are concluded. There will soon be very few vehicles coming from the Continent for which an operator's licence is needed.

THIS may be just as well. There have been complaints enough from British operators that the various items of legislation which came into effect on March 1 were rushed through Parliament and agreed in their final form on a date which allowed far too little time for operators to digest them and make the necessary arrangements. The Minister

has admitted that there will be difficulties and has promised an equal tolerance.

What, then, is due to foreign operators who are now supposed to comply with British regulations not laid before Parliament until February 26, three days before they came into effect? During the past week there may even have been vehicles arriving in Britain which left their departure point before the regulations were passed.

Officials insisting on the letter of the law might have found great satisfaction in holding up, say, a large consignment of Ruritarian goulash. The driver may have been able to produce his short-term B licence but certainly not his operator's licence. For this it would be necessary to apply "to such Licensing Authority as the Minister may from time to time direct". In