New Mexico state record. (Santa Fe, N.M.) 1914-19??, 1921-11-11
NOISY GEARS
MEAN DANCER
Tell Story Owner Ought to Inter-
Dret in Terms of Dollars
and Cents.
LACK OF OIL CAUSES TROUBLE
Study Of Rear Axle Construction and
Of Transmission Would Save Owner
Much Trouble and Some
Money.

1t is a fact that a great number of
bur cars are being driven over the
roads with noisy gears. This is being
done either through ignorance or In
lirect defiance Of that we'll established
rule "a stitch in time. etc" The noise
Of the gear besides being unpleasant,
tells a story which the owner ought to
Interpret In terms Of dollars and cents.
without knowing anything at all about
average man should be able to know
the difference between a rear axle that
Is normal and one that Is not. He may
not know the exact cause of the
trouble or the nj In which 1t MAJ
be remedied, but he certainly ought to
attention of a mechanic. The reason
for this immediate Interpretation is
TO save the owner money, for, like a
case of pneumonia developed from a
mere cold. II attention were given
early enough. the serious ailment would
o have developed. So with gears.
Once their bearings begin to wear and
so throw the gears out of their relative
running truth, the gears themselves
are affected so that If the condition Is
allowed to get worse. pretty o o the
gears cut and chip and then fail alto
gether.
Two Out Of Five Noisy.
Observations were made mt one spot
along a frequented highway, where for
hours an average OF 1000 cars per
hour passed. A fairly accurate check
was kept on gear noises on a level
stretch and without exa~ggerating,
every two cars In five had noisy rear
axles. 1t Is doubtful II the owners of
the cars realize the meaning of such
noises, and If they know that in 90
per cent Of the cases the condition
can be corrected for a few dollars, per-
haps requiring only bearing adjust
ment, shifting Of the differential, a
quart or so Of oil.
The rear axle Is not the only offender.
The transmission gears need the
same protection. but usually they are
not at fault.
In order to understand just how
noisy gears come into being, n
should study the real axle construc-
tlon. The driving pinion Mt the end of
the propeller shaft is mounted usually
on two bearings. This plnion meshes
with the large or ring gear of the diff
%ferential unit, the unit itself being
mounted on two bearings which rest
in the dlfferential housing. In order
that the ring gear and the pinlon do
their work without noise the teeth of
these gears must mesh properly. II
the correctness of the mesh Is de-
strOyed then noise results. Should the
pinion shaft (hence the plnion ITSELF
relative to the ring gear the
tooth contact Is at once changed and
you get noise. The noise Is not nee
essarily a steady one, but II may be
interrupted. due TO the fact that the
new areas Of contact of the teeth are
not all alike. There may be a high
spot on n or two or more teeth and
when these high spots are struck the
noise changes.
Lack Of fabrication.
The pinion bearings may be of the
ball or roller type and there is, In
most cars. a of adjustment OF
the bearings after they have been
worn slightly. The cause of the wear
may be natural, but in nine out Of ten
eases II is due to lack of fabrication.
The d%ifferential bearings are not I'M
ike the pinion bearings In the effect
hey have no gear noises. These bear
ngs If worn wen slightly will allow the
whole d~ifferential unit to shift side
Ways and so disturb proper gear mesh.
Dnce they start to YEA and permit
his action, the wear is rapidly accel-
rated so that in a very short time
here Is no definite tooth contact.
The time to stop the gear noises is
they appear. II is
for you and better for the car. J