How to Change a Sepantine Belt Tensioner
There are a number of reasons you may need to replace the tensioner on your serpentine belt. Perhaps the pulley is squealing indicating that the bearings are failing. Or, maybe, the spring that holds the tension on the belt is failing allowing the belt to slip. Less likely, but still a possibility, is that the pulley itself could be damaged leading to premature wear on the belt.
Fortunately, replacing the tensioner is usually a very easy do-it-yourself job. Even those with little experience should be able to complete this job in about a half of an hour.
The only tools you will need to perform this is a set of sockets and associated handles, ratchets, breaker bars and the like, suitable for working on your car. If there is adequate room in your engine compartment to easily change the fan belt without removing extra parts then this job is within reach of even the most amateur of shade tree mechanics.
The first thing to do, once you have a replacement in hand, is to remove the serpentine belt. If you haven't recently replaced the belt this is likely a good time to consider doing so. If you have a relatively new belt on the engine you can usually just remove the belt from the tensioner and leave it in place.
To remove the belt you need to release the tension. There is generally a spot on the tensioner that will accept a wrench or other device; sometimes just a half-inch socket handle such as a ratchet or breaker bar with no socket is used. By turning the tensioner against the spring tension, usually clockwise, the force is released from the belt and the belt can be slipped off of the tensioner.
Once the belt is off replacing the tensioner is generally straightforward. The tensioner will be attached to the block of the engine with two or more bolts. Using a wrench sized to fit the bolt heads, remove the bolts holding the tensioner in place. Be certain to hold onto the part as the last bolt is removed to keep from dropping it. Some of these parts are a bit heavy and there is a slight chance that if it is allowed to drop something might get damaged.
Installing the new tensioner is likewise an easy task. Put the new part in place and replace the bolts. Put the belt back on by, once again, pulling the tensioner spring tight and slipping the belt in place.
This job is actually quite easy but for the beginning do-it-yourself mechanic can bring a significant amount of satisfaction. It is a real repair, not just a maintenance task, that can be accomplished by anyone willing to give it a try.
