A M atter
Page 50
If you've noticed an error in this article please click here to report it so we can fix it.
of Adjustment
BY HANDYMAN
QUITE a number of the repair problems met with in goods vehicle operation stem from small matters of missed or incorrect adjustment and/or attention to detail. At the time these items may seem of little importance and the person dealing with them may not connect them with more vital parts of the machine. In other instances items have suffered interference and have escaped notice until a repeat repair draws attention to them in a big way. Item one is the accelerator pedal stop— and its habit of mysteriously moving out of adjustment, or disappearing altogether. Although this is just a simple item, such as a bolt and lock nut, adjustable peg or slotted bracket, if it is left off or out of adjustment, it can cause strain, rapid wear and in due course failure to fuel injection pump mechanism, mechanical governors, and venturi valves. If removed or out of adjustment, it means that at full throttle the whole weight of the driver's foot, plus whatever pressure he may exert, is being delivered right through the linkage to vital parts not intended or designed to take such loads. Venturi valve spindles and stops can be distorted, linkages and spindle clamps can be moved, and governor bearings overloaded and destroyed.
Often during some pump change or linkage repair, it is considered by the person concerned that he needs more pedal movement, and will obtain this by setting back or even removing the stop. Similarly, certain drivers have suffered some loss of power or r.p.m. and have decided that the pedal stop is in some way to blame, and have adjusted or removed the stop, probably forgetting to report this on return to base. Therefore, during any inspection of pump and controls, the pedal stop should be examined, and any defect corrected at once.
I would now refer to another matter that often escapes correct attention if the sig nificance of certain features is not understood. This is twin or triple drive V belts, coupling fan dynamo and heavy duty air pumps. All too often, during inspection, a belt is found to be on the way out, losing tension, cracking or simply worn. In a large number of instances, this single belt is replaced and all is considered well. This may not be the case at all, and on adjusting after fitting the new belt, it should be apparent that tension is not equal on all belts: it follows that the load cannot be shared either. The new belt will feel the first movement and load, the other belts will simply ride around until the new belt is worn to their level, which is very much to the detriment of' the new one.
Therefore, where double or triple V drive is needed, make sure that a matched set of belts are fitted together, this will throw up spare belts not life-expired. These need not be wasted, as it is still a normal practice to mate used belts together where their fit in the pulley and dimensions agree.
Sussex Prizewinner
THIS week's prizewinner is Mr. I. G. Harper, of Portslade, Sussex. He says that on Bedford TK tractive units fitted with 300-330 diesel engines he has found it possible to remove the engine without lifting off the cab or removing the axle. The method used is to lift the enginu out through the back of the cab—this being far easier and quicker than any other way. When the engine is seen in this position, says Mr. Harper, the job may look difficult and it may indeed seem that the engine would not come out this way. But he has removed an engine by this means in 24hours, from the time the lorry was driven in till the engine was clear of the chassis.
To get the engine out, remove the spare wheel carrier or platform which is bolted to the chassis behind the cab—the gearbox and rear engine mounting should then be removed, and the front engine mounting and all pipes, wires, and so on should be disconnected. Then, using a crane, the engine can be lifted slightly to clear the front engine mounting and then moved backwards until it will clear the chassis.
Using this method all components can be left on the engine—even the fan and fan belt. Comments Handyman: I had not thought of trying this approach, but the idea has merit and is worth trying.