The fan usually runs on ball bearings which are lubricated with a squirt can; being usually of the cup and cone type, they are adjusted by tightening the cone. The water-pump bearings are lubricated by compression grease cups; when the bearings become badly worn it is necessary to drive out the bushings and replace them; generally the shaft also will need replacing. When this shaft becomes worn out of round, no amount of tightening of the stuffing box will prevent water from leaking out.
The valve-stem guides are sometimes bushings, but more usually are holes bored through the cylinder casting. In the former case, when wear occurs the bushing may be driven out and a new one, with new valve, installed; in the latter case, the holes must be reamed true and larger, and valves with larger stems be inserted.
In the ignition system ball bearings usually are employed, with or without means of adjustment. These are lubricated with an oil can or packed in grease. There is one bearing of the ignition system which is unique in that some manufacturers advise keeping it free of lubricating substance of any kind. This is the rocker arm of the interrupter on certain makes of magnetos. Other forms of interrupters are so constructed that lubrication is advisable.
The carburetor air-valve bearing operates better if not lubricated, but does wear and need replacing at times. The throttle bearings may be lubricated and would certainly wear longer if this were done. When they do wear air is admitted which is noticeable at low engine speed, causing skipping and irregular running. Then the holes in the casting must be enlarged and larger shaft inserted.
The throttle and spark-control linkage have a number of bearings, which may be of the steel ball and socket type, or a wire bent to fit in an eye. These pins should be frequently lubricated with a squirt can. Usually they are not adjustable, so that parts must be replaced when they become badly worn.
The self-starter motor and generator are usually equipped with ball bearings and are lubricated with a squirt can. Both the motor and generator have a copper commutator on which carbon brushes bear. These are not bearings, strictly speaking, but they do require a very slight trace of oil if the brushes have not been soaked in oil. The commutator becomes worn occasionally and must be smoothed up with fine sand paper, or, if badly worn, must be removed and trued in a lathe.
The other principal bearings throughout the car are usually of ball or roller type, which may or may not be adjustable. Usually the directions for the care and replacement are given in the manufacturer’s instruction book.
In the steering gear there is a plain bronze bearing or bushing in which the shaft is set out of center, so that when wear occurs by twisting the bushing, the sector of the steering gear may be thrown deeper into mesh with the worm and take up the play.
In the transmission gear, in which all other bearings are of the ball or roller type, there will be found often a plain bearing on the forward end of the square or fluted shaft called the pilot-shaft bearing. This is one weak point in many otherwise satisfactory transmissions. When this bearing wears, the operation becomes noisy and the gears are difficult to shift. The transmission must be disassembled, the bushing withdrawn and a new one pressed in.
The steering-gear linkage bearings are usually of the ball and socket type, self-adjusting by means of springs. Steering knuckle bearings are usually bushings which may be driven out and replaced when wear occurs. It usually is necessary to replace the pins at the same time.