MAKING BEST USE OF THE FORD.
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Valuable Advice on Every Phase of Ford Transport which will Appeal to the Owner, Driver and Repairer.
561.—Assembling the Rear Axle of the Van.
One of the most awkward tasks in shops not equipped with a special axle stand is the reassembly of the rear axle of the light chassis. The axle shafts, differential and axle housings are awkward to manipulate and the fitting of the inner roller bearings is often the cause of barked knuckles and loss of temper.
To accomplish this work easily, the following procedure can be followed:— When the axle shafts have been assembled and all the differential nuts tightened and locked, while the axle is still in • the vice, position one of the thrust washers in place on its shaft, make certain that it is passed over the retaining pins and held in place by a blob of thick grease, then slip the roller hearing over the shaft and enter the shaft into one side of the axle housing. It is important to enter the shaft at the.-back of the crown wheel into the left-hand housing, otherwise the axle will run backwards. • Carry the assembly to an inspection pit. Here there is usually one board with a hand hole in it; if not, arrange two boards so that there will be a 2-in. gap between them. Up-end the housing over the hole in or between the hoards, so that the end of the axle shaft will enter this space until stopped by the inner roller bearing. Obtain a piece of stout string and pass it around the rollers in a complete loop, holding the ends of the string in line with the driveshaft opening in the housing. Ask an assistant to lift the axle a short way from the housing and pull hard at both ends of the string. This will compress the rollers evenly, and if the shaft now be lowered the rollers will enter the sleeve quite. easily. After entering, the string should be pulled away to prevent it becoming jammed.
Now position the thrust washers and roller bearing on the other shaft and lift the housing over the shaft. The axle can be inclined to assist this procedure. Place the string as before un the other bearing, have the housing lifted slightly, tighten the string and drop the housing into position.
562.—A Brake-shoe Fulcrum Repair.
When the screwed hole for the brakeshoe-support bolt in the axle casing becomes worn and the thread stripped, it is impossible to screw in a new bolt. This means either a new case or filling in the hole by welding and then drilling and retapping.
A (oink repair can be made, however, by utilizing an old spindle-body bush and filing the flange or sawing it thin and shortening the bush by the amount necessary. The head of the support bolt should also be filed or cut away until it is much thinner than formerly. the bush slipped on with the flanged end against the head of the bolt and the parts secured in the axle casing by means of a nut on the end of the n36
563.—Points in Overhauling the Engine.
In the overhaul of engines, the prim-. rice of taking up the main bearings instead ofburning them in Is often followed. This is sometimes rsatisfaetory, providing that the big-ends are not renewed or the main bearings scraped out too much.
If carried to excess, the crankshaft Is brought nearer to the top of the cylinders. In the ordinary way, if the big-ends be merely taken up, there is a corresponding shortening of the eonfleeting rods, but if the big-ends be renewed, the pistons will rise several thousandths of an inch in the cylinders. Now, the cylinder head is the same diameter as the piston, and the result may be that the pistons will foul the heads. Even if this be not the case, if the cylinders be at all worn, a sharp ridge may be formed in. each where the original stroke ended, and if the pistons rise above these ridges a metallic knock will often ensue.
In the former case, the usual cure is to chip away the sides of the combustion chambers or to turn them in a lathe. Of course, this removal of metal must not be carried to excess. It is really better to do the job thoroughly by burning-in the bearings in the proper manner.
564.—On Fitting Rings.
Too much care cannot be taken when fitting new rings as, to a great extent, the whole performance of the engine depends upon the fit of the rings. Besides ensuring a proper fit in the bore of the cylinder, care should be taken that they are a good fit in the grooves of the piston. The voracious appetite of some Fords is often due to ill-fitting piston rings.
The Ford ring is machined .003-in. taper on the outer side or face of the ring. The smaller diameter is denoted by the word "Ford" stamped on the top. The ring should be fitted with this edge uppermost, so that the wider bottom of the ring acts as a scraper to the oil on the cylinder walls, keeping it out of the combustion chamber. This taper also assists in bedding the ring into the cylinder more quickly. • The best clearance for the ring in its groove is from .001 in to .002 in. If the clearance be much in excess of this the ring will act as an oil pump, forcing oil upwards into the combustion chamber. The best gap clearances are : Top ring, .009 in. to .012 in.; middle. .006 in. to .008 in., and .004 in. to .006 in. for the bottom ring Care should be taken to see that the ring is not distorted before checking clearances, as a wrong reading can very easily be obtained. For locating distortion the ring should be checked en a surface plate, where it should lie perfectly flat for the full circumference.
In order to allow for wear in the bores of fairly old engines, the gap clearance should be taken at the bottom of each bore.