Liberty, Wrangler 2006-2007

Accessory Drive Belts

Print

Adjustment



Periodic drive belt tensioning is not necessary, because an automatic spring-loaded tensioner is used with these belts to maintain proper adjustment at all times. The tensioner is also useful as a wear indicator. When the belt is properly installed, the arrow on the tensioner housing must point within the acceptable range lines on the tensioner's face. If the arrow falls outside the range, either an improper belt has been installed or the belt is worn beyond its useful life span. In either case, a new belt must be installed immediately to assure proper engine operation and to prevent possible accessory damage.

Click image to see an enlarged view

Fig. Typical drive belt automatic tensioner wear indicator

Drive Belt Routings





Click image to see an enlarged view

Fig. Often the underhood label will display the serpentine drive belt routing



Click image to see an enlarged view

Fig. Accessory serpentine belt routing-2.4L and 4.0L engines



Click image to see an enlarged view

Fig. Accessory serpentine belt routing-3.7L engine

Inspection



Although many manufacturers recommend that the drive belt(s) be inspected every 30,000 miles (48,000 km) or more, it is really a good idea to check them at least once a year, or at every major fluid change. Whichever interval you choose, the belts should be checked for wear or damage. Obviously, a damaged drive belt can cause problems should it give way while the vehicle is in operation. But, improper length belts (too short or long), as well as excessively worn belts, can also cause problems. Loose accessory drive belts can lead to poor engine cooling and diminished output from the alternator, air conditioning compressor or power steering pump. A belt that is too tight places a severe strain on the driven unit and can wear out bearings quickly.

Serpentine drive belts should be inspected for rib chunking (pieces of the ribs breaking off), severe glazing, frayed cords or other visible damage. Any belt which is missing sections of 2 or more adjacent ribs which are 1 / 2 inches. (13mm) or longer must be replaced. You might want to note that serpentine belts do tend to form small cracks across the backing. If the only wear you find is in the form of one or more cracks are across the backing and NOT parallel to the ribs, the belt is still good and does not need to be replaced.

Click image to see an enlarged view

Fig. Typical wear patterns for a serpentine drive belt

Removal & Installation



2.4L Engine

NOTE
The belt routing schematics are published from the latest information available at the time of publication. If anything differs between these schematics and the Belt Routing Label, use the schematics on Belt Routing Label. This label is located in the engine compartment.


CAUTION
Do not let tensioner arm snap back to the free arm position, as severe damage may occur to the tensioner.


NOTE
Belt tension is not adjustable. Belt adjustment is maintained by an automatic (spring load) belt tensioner

  1. Disconnect negative battery cable from battery.
  2.  
  3. Rotate belt tensioner until it contacts its stop Remove belt, then slowly rotate the tensioner into the free-arm position
  4.  

To install:

  1. Check condition of all pulleys
    CAUTION
    When installing the serpentine accessory drive belt, the belt MUST be routed correctly. If not, the engine may overheat due to the water pump rotating in the wrong direction.

  2.  
  3. Install new belt or . Route the belt around all pulleys except the idler pulley. Rotate the tensioner arm until it contacts its stop position Route the belt around the idler and slowly let the tensioner rotate into the belt. Make sure the belt is seated onto all pulleys.
  4.  
  5. With the drive belt installed, inspect the belt wear indicator. On 2.4L Engines the gap between the tang and the housing stop (measurement A) must not exceed 24 mm (.94 inches).
  6.  

2.8L Diesel
  1. Disconnect negative battery cable.
  2.  
  3. Rotate belt tensioner until it contacts its stop. Remove belt, then slowly rotate the tensioner into the free arm position.
  4.  

To install:

  1. Check condition of all pulleys.
    CAUTION
    When installing the serpentine accessory drive belt, the belt MUST be routed correctly. If not, the engine may overheat due to the water pump rotating in the wrong direction.

  2.  
  3. Install new belt. Route the belt around all pulleys except the idler pulley . Rotate the tensioner arm until it contacts its stop position. Route the belt around the idler and slowly let the tensioner rotate into the belt. Make sure the belt is seated onto all pulleys.
  4.  

3.7L Engine
  1. Disconnect negative battery cable from battery.
  2.  
  3. Rotate belt tensioner until it contacts its stop. Remove belt, then slowly rotate the tensioner into the free arm position.
  4.  

To install:

  1. Check condition of all pulleys.
    CAUTION
    When installing the serpentine accessory drive belt, the belt MUST be routed correctly. If not, the engine may overheat due to the water pump rotating in the wrong direction .

  2.  
  3. Install new belt . Route the belt around all pulleys except the idler pulley. Rotate the tensioner arm until it contacts its stop position. Route the belt around the idler and slowly let the tensioner rotate into the belt. Make sure the belt is seated onto all pulleys.
  4.  
  5. With the drive belt installed, inspect the belt wear indicator . On 3.7L engines the gap between the tang and the housing stop ( measurement A ) must not exceed 24 mm (.94 inches).
  6.  

4.0L Engine

Because serpentine belts use a spring loaded tensioner for adjustment, belt replacement tends to be somewhat easier than it used to be on engines where accessories were pivoted and bolted in place for tension adjustment. Basically, all belt replacement involves is to pivot the tensioner to loosen the belt, then slide the belt off of the pulleys. The two most important points are to pay CLOSE attention to the proper belt routing (since serpentine belts tend to be -snaked'' all different ways through the pulleys) and to make sure the V-ribs are properly seated in all the pulleys.

Although belt routing diagrams have been included in this section, the first places you should check for proper belt routing are the labels in your engine compartment. These should include a belt routing diagram which may reflect changes made during a production run.

  1. Disconnect the negative battery cable for safety. This will help assure that no one mistakenly cranks the engine over with your hands between the pulleys, and that the cooling fan cannot activate while servicing the belt(s).
    NOTE
    Take a good look at the installed belt and make a note of the routing. Before removing the belt, make sure the routing matches that of the belt routing label or one of the diagrams in this book. If for some reason a diagram does not match (you may not have the original engine or it may have been modified), carefully note the changes on a piece of paper.

  2.  
  3. For tensioners equipped with a 1 / 2 in. (13mm) square hole, insert the drive end of a large breaker bar into the hole. Use the breaker bar to pivot the tensioner away from the drive belt. For tensioners not equipped with this hole, use the proper-sized socket and breaker bar (or a large handled wrench) on the tensioner idler pulley center bolt to pivot the tensioner away from the belt. This will loosen the belt sufficiently that it can be pulled off of one or more of the pulleys. It is usually easiest to carefully pull the belt out from underneath the tensioner pulley itself.
  4.  
  5. Once the belt is off one of the pulleys, gently pivot the tensioner back into position. DO NOT allow the tensioner to snap back, as this could damage the tensioner's internal parts.
  6.  
  7. Now finish removing the belt from the other pulleys and remove it from the engine.
  8.  

To install:

  1. While referring to the proper routing diagram (which you identified earlier), begin to route the belt over the pulleys, leaving whichever pulley you first released it from for last.
  2.  
  3. Once the belt is mostly in place, carefully pivot the tensioner and position the belt over the final pulley. As you begin to allow the tensioner back into contact with the belt, run your hand around the pulleys and make sure the belt is properly seated in the ribs. If not, release the tension and seat the belt.
  4.  
  5. Once the belt is installed, take another look at all the pulleys to double check your installation.
  6.  
  7. Connect the negative battery cable, then start and run the engine to check belt operation.
  8.  
  9. Once the engine has reached normal operating temperature, turn the ignition OFF and check that the belt tensioner arrow is within the proper adjustment range.
  10.  

 
label.common.footer.alt.autozoneLogo