PREVENTING PLAY SAVES SCRAP.
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Some Useful Pointers by Our Driver and Mechanic Readers.
TH'SCOTTISH saying, "Many a inickle makes a muekle," is very true in connection with small defects on commercial vehicles. The majority of breakdowns start in a very small way; therefore it is only common sense to nip the trouble in the bud.
A simple, but apparently sound, scheme is that forwarded by " D.P.," of Leeds, to whom this week's 15s. prize is awarded. In cases of stripped threads he obtains a piece of brass shim metal of about .002 in. thickness. When the thread of the bolt is stripped, he wraps one thickness of the brass round the bolt, leaving a small piece projecting, which is used to guide the nut over the top of the bolt. If the nut be stripped,
a brass sleeve is put in, again leaving an extra piece to guide the bolt into the hole. Instances of cures effected are given by " D.P." as follow
tension terminal on magneto distributor; leaky petrol union ; and drain tap in Ford crankcase.
crtAcK-RD bodies, such as universal
joints, sometimes cause trouble, usually due to the fracture of a keyway. To obtain and fit a new part is often a slow and expensive matter, whilst welding may not be desirable or possible.
"11.5.," of Wrexham, describes a method of repair which he practises, apparently With success. When the defective body has been removed from the shaft it is thoroughly cleaned up, afterwards being placed in a vice and pressure exerted Until the crack is closed as far as possible. The nextstep is to find a piece of mild steel of suitable strength to form a collar. Of course, the scrap-heap may contain something which, after a little work, would be satisfactory. It is essential that the inside diameter of the collar be slightly less than the outside diameter of the broken body.
The collar is heated to an even temperature, and then driven on to the body as far as necessary. A.. can of water is required to cool the coliar, but extreme care should be taken to see that no water finds its way between the body and collar, or inside the crack. The idea is, of course, to contract the collar
on to the body, therefore water must be kept away from the latter. " H.S." does not consider it necessary to peg the collar ; certainly if it be loose enough to need holding it will not be a very efficient repair. If the shape of the broken body be not round, a collar can be made to fit, care being taken to ensure accuracy of size.
ON1.1 OF the principal defects ob
served by those who inspect commercial vehicles is certainly the slackness of nuts at many points throughout the chassis and body. "D.S.," of London, deals with this matter at some length. Solid tyres are, in many cases, responsible for the prominence of the trouble, as the pneumatic tyre relieves the chassis of the perpetual minor vibrations which tend to loosen the grip of nuts, Another contributory cause is frequently the fact that insufficient or unsuitable spanners are found in the tool kit.
A very little thought will show in what ways more serious trouble may arise. due in the first instance to neglect of such an apparently trivial item As a loose nut or two. "A stitch in time saves nine" can hardly have a more correet application than in the ' matter under consideration. Without doubt it is not overstating the case to say that thousands of pounds are wasted annually in the replacement or repair of parts, which might have been saved by attention to nuts in the early stages of the development of slackness.
The shed day is obviously the occasion to rectify any looseness of nuts which may exist. In some instances a fixed time for methodical attention appears difficult to arrange, but it should certainly not be overlooked by the -user of commercial vehicles that even a few moments in the course of a week, will help materially towards the reduction of undesirable and expensive consequences. The use of satisfactory locking devices, such as are advertised in
this and associated journals, should be encouraged, • It is not possible, of course, to give our readers a complete list of the points requiring attention, with regard to loose -nuts, for all makes and types of vehicle. As a guide the following items are set forth in respect of the major units. Using this as a basis, a complete " guide card" can be compiled by users of mechanically propelled vehicles for their own information.
1. Front Axle. — Wheebretaining nuts, spring fixing -bolts, swivel pins,nuts on clevis phis or ball shanks on steering rods. . 2. Rear Axle. — Wheel-retaining nuts, spring .fixing bolts, casing bolts, truss rods, clip bolts on brake countershaft arms.
3. Frame.—Junctions of frame members (if bolts are used), spring shackles, step brackets, mountings of radiator, steering, engine and gearbox, undershield fittings, control mountings.
4. Power and Transmission Units.— Bolts at joints on crankcase, cylinder holding-down bolts, manifold boas, auxiliary mountings, cover plate bolts. flywheel retaining bolts, control mottutin§;s, universal joint bolts, clip or other bolts in brake gear.
5. Rody.—Holtling-ilown bolts, wing brackets, body fittings, lamp brackets and accessory _mouotings.