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    Cherokee, Grand Cherokee, 1999-2005

    Accessory Drive Belts

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    Adjustment




    CAUTION
    On vehicles with an electric cooling fan, disable the power to the fan by disengaging the fan motor wiring connector or removing the negative battery cable before replacing or adjusting the drive belts. Otherwise, the fan may engage even though the ignition is

    Belt tension can be checked by pressing on the belt at the center point of its longest straight span. The belt should give approximately 1 / 4 - 1 / 2 in. (6-13mm). If the belt is loose it will slip, whereas if the belt is too tight it will damage the bearings in the driven unit.

    For the purposes of V-belt tensioning, there are generally three types of mounting for the various components driven by the drive belt. The first method, referred to as pivoting type without adjuster, is designed so that the component is secured by at least 2 bolts. One of the bolts is a pivoting bolt and the other is the lockbolt. When both bolts are loosened so that the component may move, the component pivots on the pivoting bolt. The lockbolt passes through the component and a slotted bracket, so that when the lockbolt-s nut is tightened the component is held in that position. There are not automatic adjusting mechanisms used with this type of mounting.

    The second method of component mounting, referred to as pivoting type with adjuster, is almost identical except for the addition of an adjuster of some sort. Usually the adjuster is composed of a bracket attached to the component and a threaded adjusting bolt. After loosening the pivoting and lockbolts, the adjusting bolt can be tightened or loosened to increase or decrease the drive belt-s tension. With this type of mounting, you do not have to hold the component in a tensioned position and tighten the pivoting and lockbolts; the adjusting bolt does the job for you.

    Some versions of this method of mounting use an adjuster which is built into one of the components mounting braces. The brace attaches the component to the engine and incorporates a threaded adjuster in its mid-span, so that when the threaded adjuster is turned the brace shortens or lengthens. This in turn increases or decreases the amount of tension on the component.

    The third type of mounting, referred to as stationary type, is designed so that the component is mounted on its brackets. There are no pivots or lockbolts, and the component is not designed to be moved. Rather, this type of mounting uses an extra tensioner idler pulley assembly. The drive belt is tensioned by adjusting the position of the idler pulley, usually accomplished by turning the adjuster bolt on the idler mechanism.

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    Fig. A typical pivoting accessory with an adjusting bolt



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    Fig. An accessory that is fixed will have an adjustable pulley-notice the square slot to aid the 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

    Pivoting Type
    With Adjuster

    This type of drive belt is tensioned by a tensioner, which makes precise tension adjustment easy.

    1. Loosen the idelr and lockbolt which is in the center of the idler.
    2.  
    3. Turn the tensioner adjusting bolt or threaded coupling to increase or decrease the amount of tension on the drive belt, as necessary.
    4.  
    5. When the belt tension is correct, tighten the lockbolt.
    6.  

    Without Adjuster
    1. Disconnect the negative battery cable.
    2.  
    3. Loosen the component-s lockbolt and pivoting bolt only enough for the component to move.
    4.  
    5. Using a strong wooden, plastic or metal pry tool, move the component either closer to, or farther away from, the engine to provide the correct tension on the belt.
      WARNING
      If using a metal pry tool, always wrap the end with a rag or towel to prevent accidentally damaging the component from undue stress.

    6.  
    7. Once the proper amount of tension is applied to the drive belt, hold the pry tool with one hand while tightening the lockbolt securely with the other hand.
    8.  
    9. Release the pressure from the pry tool and tighten the pivoting bolt securely.
    10.  
    11. Double check the drive belt-s tension, in case the component moved slightly while tightening the bolts.
    12.  
    13. Connect the negative battery cable.
    14.  

    Serpentine Belt
    2.5L And 4.0L Engines With Power Steering

    CAUTION
    Disconnect the negative battery cable.

    Tension is maintained using an automatic tensioner pulley assembly. The drive belt is tensioned by adjusting the position of the idler pulley, accomplished by moving the adjuster bolt on the idler mechanism.

    Stationary Type
    Idler Pulley With Adjusting Bolt
    1. Loosen the idler bracket pivot bolt and locking bolts.
    2.  
    3. Adjust the belt tension by inserting the proper size ratchet in the square slot of the idler bracket and rotating the bracket until tension is applied.
    4.  
    5. While holding the tension on the belt with the ratchet, tighten the locking bolts, then the pivot bolt.
    6.  

    Idler Pulley Without Adjusting Bolt
    1. Loosen the mounting/pivot bolt behind the idler pulley.
    2.  
    3. Swivel the idler pulley with a pair of pliers or a wrench on the bearing mounting until the proper tension is achieved.
    4.  
    5. While holding the idler pulley, at the proper tension, tighten the mounting/pivot bolt.
    6.  

    Belt Tension Inspection



    Serpentine Belts

    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 in. (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



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    Fig.



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    Fig.

    V-Belts

    Although different maintenance intervals are given by each manufacturer, it is a good rule of thumb to inspect the drive belts every 15,000 miles (24,000 km) or 12 months (whichever occurs first). Determine the belt tension at a point half-way between the pulleys by pressing on the belt with moderate thumb pressure. The belt should deflect about 1 / 4 - 1 / 2 in. (6-13mm) at this point. Note that -deflection- is not play, but the ability of the belt, under actual tension, to stretch slightly and give.

    Inspect the belts for the following signs of damage or wear: glazing, cracking, fraying, crumbling or missing chunks. A glazed belt will be perfectly smooth from slippage, while a good belt will have a slight texture of fabric visible. Cracks will usually start at the inner edge of the belt and run outward. A belt that is fraying will have the fabric backing de-laminating its self from the belt. A belt that is crumbling or missing chunks will have voids in the cross-section of the belt, some times the section missing chunks will be in the pulley groove and not easily seen. All worn or damaged drive belts should be replaced immediately. It is best to replace all drive belts at one time, as a preventive maintenance measure.

    Although it is generally easier on the component to have the belt too loose than too tight, a very loose belt may place a high impact load on a bearing due to the whipping or snapping action of the belt. A belt that is slightly loose may slip, especially when component loads are high. This slippage may be hard to identify. For example, the generator belt may run okay during the day, and then slip at night when headlights are turned on. Slipping belts wear quickly not only due to the direct effect of slippage but also because of the heat the slippage generates. Extreme slippage may even cause a belt to burn. A very smooth, glazed appearance on the belt's sides, as opposed to the obvious pattern of a fabric cover, indicates that the belt has been slipping.

    Click image to see an enlarged view

    Fig. An example of a healthy drive belt



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    Fig. Deep cracks in this belt will cause flex, building up heat that will eventually lead to belt failure



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    Fig. The cover of this belt is worn, exposing the critical reinforcing cords to excessive wear



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    Fig. Installing too wide a belt can result in serious belt wear and/or breakage

    Drive Belt Routings





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    Fig. Often the under side of the hood, a label will display the serpentine drive belt routing



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    Fig. Relieve the belt tension by pivoting the automatic tensioner away from the belt, then remove the belt



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    Fig. Verifying serpentine belt alignment in the pulley



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    Fig. Accessory serpentine belt routing-Jeep Grand Cherokee 4.0L engine



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    Fig. Accessory serpentine belt routing-Jeep Cherokee 1997-02 2.5L or 4.0L engine with A/C



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    Fig. Accessory serpentine belt routing-Jeep Cherokee (right hand drive) 4.0L engine with A/C



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    Fig. Accessory serpentine belt routing-Jeep Cherokee (right hand drive) 4.0L engine without A/C



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    Fig. Accessory serpentine belt routing-Jeep Cherokee 4.0L engine without A/C



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    Fig. Fig. 51 Accessory serpentine belt routing-Jeep Cherokee 4.0L engine with A/C



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    Fig. Accessory serpentine belt routing-Jeep Cherokee 2.5L engine with A/C



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    Fig. Accessory serpentine belt routing-Jeep Cherokee 2.5L engine without A/C



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    Fig. Accessory serpentine belt routing-Jeep 4.7L Grand Cherokee engine



    Click image to see an enlarged view

    Fig. Accessory serpentine belt routing-Jeep 3.7L and 4.7L engines

    Removal & Installation



    Pivoting Type

    CAUTION
    On vehicles with an electric cooling fan, disable the power to the fan by disengaging the fan motor wiring connector or removing the negative battery cable before replacing or adjusting the drive belts. Otherwise, the fan may engage even though the ignition is OFF .

    With Adjuster
    1. Disconnect the negative battery cable.
    2.  
    3. Loosen the component-s pivot and lockbolts.
    4.  
    5. Inspect the tensioner assembly on the component; the tensioner adjusting bolt may use a locknut or screw to prevent it from loosening over time. On the type of adjuster with a threaded mounting brace, there may be two jam nuts used on either side of the threaded coupling. If such locking fasteners are found, loosen them.
    6.  
    7. Turn the tensioner adjusting bolt or threaded coupling to relieve all tension from the drive belt until the most possible slack is gained from the component.
    8.  
    9. Slip the belt off of the accessory pulley, then remove it from the other pulleys. Remove the belt from the vehicle.
    10.  

    To install:

    1. Route the new belt on the component pulleys. Make certain that it is routed correctly; incorrect routing could cause a component to spin backward, possibly damaging it.
    2.  
    3. Once the belt is correctly positioned on all of the pulleys, adjust the tension as described earlier in this section.
    4.  
    5. Connect the negative battery cable.
    6.  

    Without Adjuster
    1. Disconnect the negative battery cable.
    2.  
    3. Loosen the accessory's slotted adjusting bracket bolt. If the hinge bolt is excessively tight, it too will have to be loosened.
    4.  
    5. Push the component toward the engine to provide enough slack in the belt so that it will slide over one of the accessory drive pulleys. Remove the drive belt from the accessory drive pulleys and from the vehicle.
    6.  

    To install:

    1. Position the new drive belt over the component pulleys. Make sure that it is routed correctly.
    2.  
    3. Adjust the tension of the belt, as described earlier in this section.
    4.  
    5. Connect the negative battery cable.
    6.  

    Serpentine Belt

    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 diagram. 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.  

    Stationary Type
    Idler Pulley With Adjusting Bolt
    1. Disconnect the negative battery cable.
    2.  
    3. Loosen the idler bracket pivot bolt and locking bolts.
    4.  
    5. Move the idler pulley until the most amount of slack is gained.
    6.  
    7. Remove the drive belt from the accessory pulley, then from the other applicable pulleys.
    8.  

    To install:

    1. Position the new belt over the crankshaft pulley, the idler pulley and the accessory pulley. Make certain that it is correctly routed, otherwise it could cause the accessory to be rotated backwards. This could cause damage to the accessory.
    2.  
    3. Adjust the belt tension, as described earlier in this section.
    4.  
    5. While holding the tension on the belt with the ratchet, tighten the locking bolts, then the pivot bolt.
    6.  
    7. Connect the negative battery cable.
    8.  

    Idler Pulley Without Adjusting Bolt
    1. Disconnect the negative battery cable.
    2.  
    3. Loosen the mounting/pivot bolt behind the idler pulley.
    4.  
    5. Remove the drive belt from the accessory pulley, then from the other applicable pulleys.
    6.  

    To install:

    1. Position the new belt over the crankshaft pulley, the idler pulley and the accessory pulley. Make certain that it is correctly routed, otherwise it could cause the accessory to be rotated backwards. This could cause damage to the accessory.
    2.  
    3. Swivel the idler pulley with a pair of pliers or a wrench on the bearing mounting until the proper tension is achieved.
    4.  
    5. While holding the idler pulley, at the proper tension, tighten the mounting/pivot bolt.
    6.  
    7. Connect the negative battery cable.
    8.  

    V-Belts

    If a belt must be replaced, the driven unit or idler pulley must be loosened and moved to its extreme loosest position, generally by moving it toward the center of the motor. After removing the old belt, check the pulleys for dirt or built-up material which could affect belt contact. Carefully install the new belt, remembering that it is new and unused; it may appear to be just a little too small to fit over the pulley flanges. Fit the belt over the largest pulley (usually the crankshaft pulley at the bottom center of the motor) first, then work on the smaller one(s). Gentle pressure in the direction of rotation is helpful. Some belts run around a third, or idler pulley, which acts as an additional pivot in the belt's path. It may be possible to loosen the idler pulley as well as the main component, making your job much easier. Depending on which belt(s) you are changing, it may be necessary to loosen or remove other interfering belts to get at the one(s) you want.

    When buying replacement belts, remember that the fit is critical according to the length of the belt (-diameter-), the width of the belt, the depth of the belt and the angle or profile of the V shape or the ribs. The belt shape should match the shape of the pulley exactly; belts that are not an exact match can cause noise, slippage and premature failure.

    After the new belt is installed, draw tension on it by moving the driven unit or idler pulley away from the motor and tighten its mounting bolts. This is sometimes a three or four-handed job; you may find an assistant helpful. Make sure that all the bolts you loosened are tightened and that any other loosened belts also have the correct tension. A new belt can be expected to stretch a bit after installation so, be prepared to readjust your new belt, if needed, within the first two hundred miles of use.

     
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