Alternators are often written off as “wear items” that, like belts, hoses, and tires, will simply wear out over time. While that’s true to a certain extent, it’s also true that preventative maintenance can effectively extend the operational lifespan of an alternator. The specific maintenance operations will vary from one alternator to another, but mitigating the effects of heat, vibration, and external contaminants should always be at the top of any list.
Why Do Alternators Fail?
Alternators fail for a variety of reasons, but most failures can be traced back to three main factors: heat, vibration, and external contaminants. Some components can also be damaged by other external factors, like an over-tightened belt or chronically discharged battery, and other components simply wear out over time.
Dealing With Heat, Vibration, and External Contaminants
The most important part of any alternator preventative maintenance schedule is a thorough visual inspection. Since heat is one of the leading causes of alternator failure, it’s absolutely vital to check out your alternator’s cooling system on a regular basis. If the unit is air-cooled, then this process just involves checking the vents for obstructions and ensuring the fan (if it has an external fan) is in good condition. However, some heavy duty alternators use liquid or oil cooling. If your alternator is oil-cooled, it is critical to ensure that the oil is maintained through regular manufacturer recommended oil-change intervals. Ensure oil lines don’t have and bends or kinks and ensure that any vent or drain lines are clear.
Since excessive vibration can also lead to a premature failure, it’s also important to check an alternator’s mounting bushings when performing preventative maintenance. If the bushings wear out, and they aren’t replaced, excessive vibration can lead to the premature failure of internal components. Loose bushings can also cause other problems if the alternator is grounded through its mounting hardware. Ensure the mounting hardware is secure and has not vibrated free.
The last thing to check for during a visual inspection is the presence of external contaminants like dirt and dust. Dirty electrical connections can put the same sort of strain on an alternator as a discharged battery, which can lead to premature failure, and other contaminants like coolant and oil may damage internal components if they get inside a unit.
Other External Factors
Some external factors, like an over-tightened drive belt, can also cause an alternator to fail prematurely. In the same way that a loose belt can prevent an alternator from charging properly, an overly tight belt can overload and damage the alternator bearing, which is why it’s important to check belt tensions on a regular basis.
An alternator may also fail prematurely if it is constantly overworked due to poor electrical connections or battery issues. This problem can be dealt with by load testing the battery on a regular basis in addition to checking and cleaning the battery terminals, cable ends, and the electrical connections on the alternator itself.
Replacing Worn Out Components
In addition to mitigating the effects of external factors like heat, vibration, and contaminants, you can also prolong the life on an alternator by replacing certain components before they wear out. For instance, some manufacturers recommend that you check the regulator and brushes every 12 to 24 months. If the brushes are out of spec, this provides an opportunity to replace them before they actually fail.
Although replacing components like brushes before they fail won’t prolong the life of an alternator indefinitely, it can help prevent sudden failures and keep your vehicle on the road longer. Click here to see the complete alternator units we carry.