WHAT NOISE MAY MEAN

Dominion, Volume 19, Issue 94, 15 January 1926, Page 6

WHAT NOISE MAY MEAN

It has been said with a certain amount of truth, that noise is always accompanied by needless wear and loss of energy and power; and it would be all to the good if that statement _ were taken as the literal truth and invariably applicable to motor vehicles of all kinds. The result might well be that more notice would be taken of "unauthorised” noises issuing from a chassis and body; and that, by their receiving earlier attention and elimination of Tie maintenance costs, especially those caused by the need for new parts and repairs, would be appreciably reduced in the long run. Although it would be an exaggeration to assert that every wrongful noise from a car infers that all the parts from which its "components” arise are wearing more rapidly than need lie, or are absorbing energy that should be de-

voted to driving the vehicle, that view would not be found very far from wrong if the points were considered. A rattle from brake joints may not mean any practical waste of useful energy, but it will imply that the looseness is giving rise to vibration and "hammering” between the units of each joint, causing the rate of wear to (ncrease continually. The more a part wears, the quicker it wears, is one way of expressing the idea in mind A big-end bearing, for example, that has developed a few thousandths of an inch slackness after 10 or 20 thousand miles running, may hammer itself away to treble the extent in the succeeding SOGO miles,' and thereafter the rate of wear will "increase and multiply” out of all proportion to the previous rate.

If a bearing shell is taken up (i.e., adjusted) with the minimum of delay, every lime its looseness causes noise, it may last indefinitely, even up to 100,000 miles; but if the noise be ignored so long as the engine will run, a new bearing will probably be required.