Wash out the housing every five thousand miles, and replace the lubricant, as small metallic particles are worn off the gear teeth and this grit, which is destructive to the gears and bearings, mixes with the grease making it necessary to remove it that often.
A grease cup will be found located at the outer end of each half of the axle housing, which supplies the lubricant for the outer bearing. This grease cup should be filled weekly with a medium cup grease and given a half turn each day.
Care of Front Axle.—Pack the space between the bearings in the hub of the wheel every thousand miles. Use a heavy cup grease. The king bolts which hold the steering knuckles between the ends of the yokes are hollow and carry a grease cup on the head, which forces the grease out through finely perforated holes, and lubricates the bushings on which the pins take their bearing. This cup should be filled weekly and given a half turn each day.
CHAPTER XXXIII
BRAKE TYPES, OPERATION AND CARE
An automobile is always equipped with two sets of brakes, as they are required by law. The functional action of the brakes is to check the motion of the car when the driver wishes to stop or reduce the rolling speed. The service brake usually operates on the external surface, or on the outside of the drum flange, and is connected to the right foot pedal through a set of linkage. The emergency brake operates on the internal surface of the drum, and connects through linkage to a hand lever operating on a notched quadrant. The service brake is used in ordinary driving to check the rolling motion and to stop the car. The emergency brake is used to assist the service brake and to hold the car, in case the driver wishes to allow it to stand on a grade.
[Fig. 124] shows a set of brakes assembled on the axle ready to receive the horizontal flange of the brake drum. The brake drum is attached to the wheel; consequently when a wheel has been removed and is about to be replaced, the first operation consists of starting the drum flange into the space between the lining of the external and internal bands; care should always be exercised in making this adjustment, in order not to burr the outer edge of the lining, as a brake with an uneven frictional contact surface is of little value in checking the motion of the car.
In [Fig. 124], A shows the position of the band on the inside of the drum; B shows the contracting tension coil spring which holds the bearing surfaces of the band in contact with the flat surface of the cam when the brake is not in use; C shows the cam shaft, and the flat surfaces of the double action cam, which expands the band and brings it into even contact with the inner horizontal surface of drum flange, thereby checking the motion of the wheel by frictionally grasping the drum.
The service brake shown in [Fig. 124] is of the external contracting type, which operates on, or frictionally grasps the outside horizontal surface of the drum. D shows the lined band, which is held in a stationary position from the rear; E shows the leverage arrangement with its expanding coil spring, which holds the band free from the drum, when the brake is not in use; F is the lever to which the pull rod is connected; G is the lever on the internal brake cam shaft to which the hand lever is connected by the pull rod.
Fig. 124. Brake—Types and Adjustment