How do I Replace a 4Runner Alternator Belt?by Grace Mclain
The Toyota 4Runner model vehicles come equipped with two different types of alternator belts. The first belt is a V-belt that controls each engine accessory separately. The second belt is a serpentine belt that controls the alternator and all of the other engine accessories at the same time. The main responsibility of the belt is to control the alternator while the engine is running. If the belt has cuts, chafing or excessive cracking, replace the belt as soon as possible to prevent the belt from breaking.
V-Belt Replacement Procedure
Open the hood and locate the alternator. The alternator will be at the driver side top of the engine. Locate the pivot bolt below the alternator. Loosen the pivot bolt with the ratchet and a socket.
Locate the adjustment bracket on the top of the alternator. Loosen the locking bolt in the center of the adjustment bracket slide with the ratchet and a socket. Locate the adjustment bolt at the end of the bracket. Turn the bolt counterclockwise to loosen the belt.
Pull the belt out of the pulleys and out of the engine area. Route the new belt around the pulleys and repeat the process for tightening the belt. Once the belt is tight, push inward on the belt with your hand. If the belt has more than 1/2 inch of free play, then the belt will need to be tightened more until there is no more than 1/2 inch of free play.
Inspect the belt to make sure it is seated inside the pulleys. Crank the engine and let it run for about 10 seconds. Inspect the belt again and close the hood.
Serpentine Belt Replacement Procedure
Open the hood and locate the routing diagram for the serpentine belt. The routing diagram for the 4Runner model vehicles is stamped to the top of the fan shroud or the underside of the hood. Use the diagram when installing the new belt.
Locate the automatic belt tensioner on the front of the engine. The tensioner has a spring loaded component on one end and a roller pulley on the other end. Use the bolt in the center of the roller pulley to turn the tensioner device.
Turn the tensioner device counterclockwise until the belt is loose. Pull the belt out from under the roller pulley. Release the tensioner and pull the belt out of the other pulleys. Pull the belt out of the engine compartment.
Route the new belt around the accessory pulleys as directed by the belt routing diagram. Inspect the new belt to make sure that it is properly routed and properly seated inside of the pulleys.
Crank the engine and let it run for about 10 seconds. Turn the engine off and inspect the belt again, then close the hood.
- If the diagram for the serpentine belt has faded away, use a pen and a piece of paper to write down the routing direction of the old belt.
- Both the V-belt and the serpentine belt can be purchased at most any auto parts store.
- Always remove the keys from the ignition before working inside of the engine compartment. This will prevent anyone from accidentally cranking the engine.
Items you will need
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