GARAGE AND WORKSHOP NOTES.
Page 69
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Useful Contributions From Our Driver and Mechanic Readers.
Removing Bushes and Shafts.
FROM Norwich " J.W.T." sends us some useful information on the removal of bushes from their bosses and the driving out of shafts from such fittings as sprocket wheels.
Having to do repair jobs in all sorts of places where no appliances for such work are at hand is a valuable education, as it sharpens up one's wits and develops one's inventive faculties.
The driving out of bushes and the driving in of new ones, the removal of shafts from sprocket wheels, etc., are jobs that should be done under a press. Now a press that is worthy of the name and is powerful enough for the work in connection with commercial vehicles is a rather costly article, and only the larger garages can afford such a luxury. A very good substitute can, however, be improvised at the cast of a few shillings. I have had to install such a gadget for one job only, and even then it was less costly than taking the job to be done to the nearest garage where a press was to be found large enough for commercial work.
The device simply consists of a tube, about 4 ft. or 5 ft. long, and a shaft that will slide freely through it. The diameter and length of the sliding part depend upon the character of the work to be done. A cross-hole is drilled at the top of the sliding member and a hole leading to it, as in a sash weight. This enables a cord to be attached to it and to be passed over any old pulley that may be handy.
In the ease of a shaft that is fast in a wheel it is only necessary to screw something, such as a nut, on the end of the shaft, if there be a screw thread, put the wheel on some heavy support and place the tube over the end of the shaft, taking care to hold the tube upright; the inner member, which forms the ram, is then lifted and the cord let go slack, giving it a jerk so that it does not drag on the pulley, and the ram will fall with unerring certainty on the end of the shaft, and if the lift be great enough, the ram heavy enough, the support or anvil firm enough and the blows repeated often enough, this device will shift anything—even things that the strongest garage type of press has failed to move.
Por driving bushes in or out this device is equally useful, as the blow can be regulated so that it would hardly crack a Brazil nut by allowing only a very slight fall of the ram; yet, if raised to its full height, it can tackle the most obstinate cases.
The end of the tube can be held in exactly the place where the blow is required, and above all features it has the virtue of striking the blow in a perfectly straight line. A plug, such as that shown, will remove any hush from such an article as a lorry wheel, which is usually too large to go under the ordinary press. In pressing in new bushes it is well to see that about half an inch of the bush enters the hole so as to act as a pilot, and if the tube be held straight the bush will go in straight. " J.W.T." has used old axles for this purpose, but if nothing of the kind be available a piece of bar-iron and a piece of large gas-pipe will answer well and can be bought anywhere. Gaspipe can usually be procured up to 2-in. bore, and any old shaft or bar of iron will do for the ram.
Facilitating Spring Repairs.
GREAT difficulty is often experienced when fitting new leaves to rear springs in keeping the spring compressed while the dowel pin is riveted over, especially, says " C.V.B.," of Southampton, when one has not the necessary clamps ; even then they are apt to slip and the leaves will fly 'apart, often hurting the operator.
Much time and trouble can be saved by the following simple idea.
Drill a holding-down plate in. clearance, put the leaves of the spring together (including the holding-down plate), measure from the bottom leaf to the top plate, allowing about 1 in., or sufficient to take a nut ; this will give the length of dowel pin required ; turn up a fin, pin, or any local blacksmith will make it in a very short time, and thread it for about 3 ins. or 4 ins. down.
Now grip the dowel tightly in the vice and build up the spring. By screwing down the nut the leaves will be compressed quite easily.
After the spring is put up and bolted down securely to the axle, the nut can be tightened up hard, the pin cut oft just above the nut and finally riveted over, but it may be found better to leave the pin uncut, then in case of any further spring trouble the same pin will do again.
Assembling Split-cone Valve Cotters.
A VERY useful hint for assembling split-cone type valve cotters is sent by " S.V.I41.," of Bristol.
This type, of which we give diagrammatic drawing, is now largely used on the modern engine and unless the job be tackled in this way it becomes a risky, finger-pinching and patience-wasting operation.
When assembling the cotter first smear the groove of each half with some stiff grease. Then lift the valvespring collar and press each cotter gently home on the valve stem. The cotter will then remain fast on the stem, so permitting the head to be kept clear while the spring collar is lowered down over the cotter.
Sometimes, especially in vehicles in which the driver sits over the engine, the valves are very difficult to get at. When this is the case smear the tip of the thumb and first finger with grease and each cotter will then adhere to their tips sufficiently firmly to enable them to be located and pressed home on the valve stem, when the fingers can be drawn clear.
This method has been used for years by " S.V.M." with good results, and wherever adopted has been acclaimed a great success.