How to Loosen a Tensionerby Jody L. Campbell
There are three ways to loosen tension on a drive belt, depending on the vehicle. The most common way in today's vehicles is an automatic belt tensioner. This application is used on serpentine belts, which connect to every pulley of the engine. Older vehicles may have drive belts that were removed by pivoting an alternator to release tension. Import vehicles often use a combination of serpentine and V-belts on the pulley system. These use a combination of an adjuster bolt and loosening a pulley to extract the belt.
Open the hood and locate the drive belt(s). Either locate the serpentine belt routing diagram in the engine compartment, or refer to the repair manual.
Determine the type of tension applied to the belt you're replacing. Often, if the belt routing diagram can be located, it will display if an automatic tensioner is being used. If you only have one belt connected to all of the pulleys of the vehicle, then you have an automatic belt tensioner.
Locate the belt tensioner per belt routing diagram. The automatic tensioner is a pulley on a pivoting bracket. To relieve the tension, a tool is inserted onto the pulley or a square drive is provided to insert a tool or ratchet. Apply the correct tool the tensioner calls for, and turn the tool counterclockwise to loosen the tension. While holding the tool in place with the tension relieved, slip the belt off the most accessible pulley that you can reach.
Loosen the two (or three) bolts on the alternator, on older vehicles that do not have an automatic belt tensioner. If you inspect the alternator, you will notice it is attached to a bracket with a curved slot. Loosening the bolts of the alternator will allow you to pivot the alternator along the curved slot and release tension to remove the belt. To apply tension, reverse the procedure.
Locate the adjusting bolt bracket on an import vehicle to loosen the tensioner. Most often this bracket is located near the alternator. Loosen the bolt with a ratchet and socket until tension is relieved on the belt. Locate the idler pulley and loosen the center retaining bolt using a wrench and turning the bolt counterclockwise. Once you can wiggle the pulley, you will be able to remove the belt from the pulley groove.
- Some vehicles have extremely tight engine compartments that make access to the drive belts difficult. Always refer to a repair manual before attempting to replace a drive belt. You might find out removing a wheel and a fender well splash shield is required to access the tensioner.
Things You'll Need
- Box and hand wrench set
- Belt removal tool
- Ratchet and socket set
- Repair manual
Jody L. Campbell spent over 15 years as both a manager and an under-car specialist in the automotive repair industry. Prior to that, he managed two different restaurants for over 15 years. Campbell began his professional writing career in 2004 with the publication of his first book.