Are there other parts I need to replace when replacing my alternator?
If you decide to replace your alternator, there are several other parts that you should update at the same time. Removing the alternator usually requires removal of the serpentine or accessory belt and the lifespan of most modern serpentine belts is much less than the lifespan of the vehicle’s alternator. 60,000 to 100,000 miles is typically the most you can get out of a belt, while an alternator may last 150,000 or more miles without complaint. If you’ve never replaced your serpentine belt, you should definitely do so when servicing the alternator.
A major factor on the longevity of your alternator is maintaining proper tension on the pulley from the serpentine belt. If there is too much tension on the alternator pulley, it can lead to damaged rotor shaft bearings. If there is not enough tension, the belt can slip, and it will cause your alternator to produce inconsistent power. The tensioner pulley is responsible for keeping the appropriate level of tension on all the pulleys that the serpentine belt drives and it is also a wear item. If your vehicle has a manual tensioner that you adjust by turning a screw or bolt, or an automatic spring-loaded tensioner, the bearings will eventually wear out, and the spring in an automatic tensioner can wear out, as well.
There will also often be idler pulleys that you can easily replace – usually they’re attached with a single bolt and washer and take only a few minutes to swap out. The serpentine belt is often available as a package to deal with any tensioners and idlers that you require. It’s prudent to replace them all at the same time for a small additional cost to the alternator replacement bill.