Arizona republican., 1919-07-27
Get Acquainted With Your Car
"A LITTLE ADVICE NOW AND THEN
 IS RELISHED BY THE BEST OF MEN"

Among the hardest working units in the mechanism of the modern motor rar is the rear axle. The function of tiis part is not only t0 help carry the weight of the car but also to transmit the power. Whenever the car Is in motion the rear axle is the scene of intense mechanical activity. It will be obvious then that this part of the mechanism should have the most scru- pulous care. It does not always get it as we shall point out in the course of this article.
 Rear axles fall readily into two dis tinct classifications, dead axles and live ones It is live axles which arc used on all modern passenger cars. The term Hive" simply means that the axle turns. Dead aXles do not turn and they are only used on vehicles having double chain drive
 When we come to examine live axle. We find it necessary 10 classify them still further into three minor classes, known respectively as froating, semi floating and three-quarters floating, according to the type of gearing used to transmit the power
 The live axle consists principally Of a hollow spheroid, from which project OH FlGleI sue two luptS. III lle cen tral spheroid is located the differential unit embodying a number of gears. From the differential project two shafts which occupy the tubes project ing from the central spheroid of the rear axle. At the ends of these shafts the wheels arc attached.
 The ciassifications of floating, semi floating and three quarter floating are derived from the method used in at taching the wheels to the shaft.
 The floating axle does do very nearly that thing It is not called upon to bear any of the weight of the car, il simply transmits the power to the wheels and takes a little of the tor slonal or twisting stresses. The float ing axle has its bearings outside of the tube so that the wheels really rest on the tubes and not on the shafts. In this type of axle the shafts may be removed without disturbing any other parts.
 The semi-floating axle has it's bear ings on the inside of the tube, so tha- the shafts are called upon to beal some of the load as well as to trans init power. The shafts are not a: easily removed as in the case of the floating axle.
 The three-quarter floating axle has tle DedTlnsS on the OulSlde or the tuDes and there is a rigid connection betweer shafts and wheels. This type demands that the shafts shall bear some of the load in addition to transmitting power When it comes to the types of gear. used in transmitting power, we finC that the passenger cars of today em ploy three straight bevel, spiral beve and two speed bevel. In the truck fielC we find three additional types, tn worm, internal gear and double chail drive, though the latter is growing les every year. During the last few year the spiral bevel has come rapidly t, the front until today it is the mos popular type. There are obvious req sons for this, it's quiet running ant general efficiency being the leadin; ones. Many makers still stick to tn straight bevel. while the two speed bevel has only only one prominen adherent.
 The car owner who has experiences that most tenacious trouble commonl. known as rear axle trouble" will no need the advice to do everything pos aible to guard against it. Many seli ous troubles may devC,op in this uni