Volkswagen Cars 2000-05

Accessory Drive Belts 3

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Inspection




NOTE
To access the front of the engine on the Audi A4 and 1998 and later Passat models, the lock carrier for the hood latch must be placed in the service position.

As drive belts wear, they tend to stretch, or lengthen. As a belt stretches over time, the tension decreases, which causes the belt to slip on the pulleys. This slippage not only causes operating problems (erratic steering, high engine temperatures, and charging system problems), but also can greatly accelerate wear and damage to the belts themselves. Excessive slippage can cause a drive belt to glaze, overheat, and eventually break. Regular inspection and adjustment of the accessory drive belts will prolong their life, and ensure proper operation of belt-driven components.

To thoroughly inspect accessory drive belts, it's advisable to remove the lower engine cover, and view the condition of the belts through the right front wheel housing. If necessary, raise and safely support the vehicle to allow access. Viewing the belts from the engine compartment is sometimes possible, but belt-driven components such as the power steering pump and air conditioner compressor are often out of view from the engine compartment.

Inspect the belts for signs of glazing or cracking. 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. All worn or damaged drive belts should be replaced immediately. It is always best to replace all drive belts at one time, as a preventive maintenance measure, during this service operation.



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Fig. Early tensioners such as the gear type are shown here



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Fig. Simply turn the gear type with a wrench to adjust



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Fig. Once the belt is loosened, slide it off the pulleys to remove it



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Fig. ALWAYS mark the direction of rotation of a belt BEFORE removal



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Fig. Some tensioners may be of the gear type such as the one shown here



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Fig. Simply turn the gear type with a wrench to adjust



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Fig. Once the belt is loosened, slide it off the pulleys to remove it

As drive belts wear, they tend to stretch, or lengthen. As a belt stretches over time, the tension decreases, which causes the belt to slip on the pulleys. This slippage not only causes operating problems (erratic steering, high engine temperatures, and charging system problems), but can greatly accelerate wear and damage to the belts themselves. Excessive slippage can cause a drive belt to glaze, overheat, and eventually break. Regular inspection and adjustment of the accessory drive belts will prolong their life, and ensure proper operation of belt-driven components.

To thoroughly inspect accessory drive belts, it's advisable to remove the lower engine cover, and view the condition of the belts through the right front wheel housing. If necessary, raise and safely support the vehicle to allow access. Viewing the belts from the engine compartment is sometimes possible, but belt-driven components such as the power steering pump and air conditioner compressor are often out of view from the engine compartment.

Inspect the belts for signs of glazing or cracking. 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. All worn or damaged drive belts should be replaced immediately. It is always best to replace all drive belts at one time, as a preventive maintenance measure, during this service operation.

Inspect the drive belt for signs of glazing or cracking. 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. All worn or damaged drive belts should be replaced immediately.

  1. Turn the engine at vibration damper/ belt pulley with a suitable socket wrench.
  2.  
  3. Raise the vehicle, then check the drive belt (1) for:
    1. Sub-surface cracks (cracks, core ruptures, cross sectional breaks)
    2.  
    3. Layer separation (top layer, cord strands)
    4.  
    5. Base break-up
    6.  
    7. Fraying of cord strands
    8.  
    9. Flank wear (material wear, frayed flanks, flank brittleness -glassy flanks-, surface cracks)
    10.  
    11. Traces of oil and grease
    12.  

  4.  
  5. Replace the belt if any damage is found to avoid any break-downs or operating problems.

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    Fig. Use wrench to turn the engine at vibration damper/belt pulley, then raise the vehicle and inspect the belt (1)

  6.  

Tension Measurement


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Fig. Adjust tension by loosening both the pivot bolt and the upper adjustment bolt


NOTE
To access the front of the engine on the Audi A4 and 1998 and later Passat models, the lock carrier for the hood latch must be placed in the service position.

To check belt tension on V-belts, push in on the drive belt about midway between the crankshaft pulley and the driven component. If the belt is less than 39.4 in. (1m) long, it should deflect between 1 / 16 - 1 / 8 inch (2-5mm). For longer belts, it should deflect between 3 / 8 0.40- 5 / 8 inch (10-15mm). Belt size is usually printed on the back side of the belt. If it can't be read, it's probably time to replace it.

To compensate for the stretching of the accessory drive belts, a means of adjustment is necessary. This can be accomplished by changing the distance between the crankshaft pulley and the driven component, or by means of a tensioning device using an idler roller.

The current trend for most manufacturers is the use of a serpentine type drive belt that is kept in adjustment using an automatic belt tensioner. These automatic tensioners can be either a pivoting arm-type or an eccentric type.

The rotary method (most common with V-belts) involves the driven component being rotated on a pivot. A slotted bracket and or arm(s) is/are used to hold the component in place once the belt tension is set. Within this method, there are four variations. The most basic variation is a simple slotted bracket with a bolt. This requires pulling or pushing on the driven component to achieve the desired belt tension. Some early models use a spring-loaded alternator bracket that sets the belt tension after the slotted bolt is loosened.

Other models use a rack and pinion design on the slotted adjustment bracket. This allows for effortless belt adjustment, since the pinion gear has a hex head and can be turned with a wrench to make adjustments. The final variation of the slotted style adjustment design uses a long adjuster bolt that pushes or pulls the driven component once the slotted bolt is loosened.

Poly-Ribbed Belts

The engines equipped with poly-ribbed belts are equipped with automatic adjusters, and Do NOT require adjustment. The spring action of the tensioner compensates for the stretching of the belt. The belts should be checked for belt stretch, wear or fluid damage and replaced if necessary. Check the maintenance recommendation chart for recommended routine replacement intervals.

V-Belts
Plain Slotted Brackets


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Fig. Alternator mounting with slotted brackets

  1. As a safety precaution, disconnect the negative battery cable.
  2.  
  3. Loosen the adjustment nut/bolt in the slotted bracket. Slightly loosen the pivot bolt.
  4.  
  5. Pull (don't pry) the component outward to increase tension. Push inward to reduce tension. Tighten the adjusting nut/bolt and the pivot bolt.
  6.  
  7. Recheck the drive belt tension, readjust if necessary.
  8.  
  9. Reconnect the negative battery cable.
  10.  

Rack And Pinion-Type Slotted Brackets


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Fig. Loosen the tension bolt (shown) and the alternator pivot bolt until the alternator swings freely under its own weight



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Fig. Adjust the V-belt by turning the nut on the tension bolt

  1. As a safety precaution, disconnect the negative battery cable.
  2.  
  3. Loosen the alternator pivot bolt, and the slotted bracket bolt, and the bracket mounting bolt.
  4.  
  5. Adjust the V-belt by turning the large nut (the pinion) nut while checking the belt deflection.
  6.  
  7. While holding the pinion nut steady, tighten the slotted bracket bolt to hold the adjustment setting.
  8.  
  9. Tighten the alternator pivot bolt, and the slotted bracket mounting bolt.
  10.  
  11. Recheck the drive belt tension and readjust if necessary.
  12.  
  13. Reconnect the negative battery cable.
  14.  

Slotted Brackets With Adjustment Bolt


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Fig. Some components, like this air conditioner compressor, use a slotted bracket with an adjustment bolt. To adjust the tension, loosen the slotted bracket bolt . . .



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Fig. . . . and turn the adjustment bolt as necessary to achieve the proper belt tension

  1. As a safety precaution, disconnect the negative battery cable.
  2.  
  3. Loosen the slotted bracket bolt(s), and slightly loosen the pivot bolt(s).
  4.  
  5. If equipped, loosen the locknut(s) on the adjustment bolt(s).
  6.  
  7. Turn the threaded adjustment bolt(s) as necessary to achieve the correct tension.
  8.  
  9. Tighten the pivot bolt(s) and the slotted bracket bolt(s) securely.
  10.  
  11. While holding adjustment bolt(s) in position, tighten the lock nut(s) if equipped.
  12.  
  13. Recheck the drive belt tension and readjust if necessary.
  14.  
  15. Reconnect the negative battery cable.
  16.  

Removal & Installation




NOTE
To access the front of the engine on the Audi A4 and 1998 and later Passat models, the lock carrier for the hood latch must be placed in the service position.

If a belt must be replaced, the driven component must be loosened and moved to its extreme loosest position (usually by moving it toward the center of the motor). On models with automatic belt adjusters, the tensioner is moved to release tension on the belt, and then the belt is removed.

  1. After removing the old belt, check the pulleys for dirt or built-up material which could affect belt contact.
  2.  
  3. Carefully install the new belt, 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.
  4.  


NOTE
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.

The 1.8L engines use three dive belts, two multi-ribbed, and a V-belt. The alternator, cooling fan and power steering pump are driven by a serpentine belt that is tensioned by a conventional automatic tensioner. The water pump is drive by second pulley mounted to the power steering pump. A separate multi-ribbed belt drives the air conditioner. It uses a tensioning roller that must be preloaded and tightened in place to tension.

  1. To remove and install the belts on the 1.8L engine, proceed as follows:
  2.  
  3. On 1.8L engines the water pump pulley is a split sheave type pulley. To remove the water pump drive belt:
  4.  
    1. First remove the multi-ribbed drive belt.
    2.  
    3. Use an open-end wrench to loosen the tensioner. Move the tensioner until the tensioner and housing holes align, then place a suitable hex tool or drift into the aligned holes to keep the tensioner retracted.
    4.  
    5. Remove the belt.
    6.  
    7. Counterhold the viscous fan pulley using a suitable drift.
    8.  
    9. Remove the pulley fastener using an 8 mm hex wrench, and then remove the fan along with the fan pulley.
    10.  
    11. The water pump drive belt is removed by removing the fasteners for the pump's pulley. Counter hold the power steering pump pulley to allow for removal of the water pump pulley by placing a suitable dowel through the upper back side of the power steering pump pulley.
    12.  
    13. During assembly, rotate the power steering pump occasionally to properly seat the belt. There is no adjustment shims available, therefore if the belt is in need of replacement, an exact original fit must be used. If the belt is too loose it will slip, and if too tight it will damage the bearings of the power steering pump and water pump, causing a premature failure.
    14.  
    15. The rest of the reassembly procedure is in reverse order of removal.
    16.  

  5. To remove the air conditioner belt:
  6.  
    1. Loosen the two fasteners for the tensioner assembly
    2.  
    3. Move the tensioner to slacken the belt.
    4.  
    5. Remove the belt.
    6.  
    7. Reassemble in reverse order of removal. Tension the belt by applying an 18 ft. lb. (25 Nm) load on the tensioner assembly and tightening the fasteners.
    8.  


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

After the new belt is installed, adjust it for proper tension. This is sometimes a three or four-handed job; you may find an assistant helpful. Make sure that all the bolts you loosened are retightened and that any other loosened belts have the correct tension. A new belt can be expected to stretch a bit after installation so be prepared to re-adjust your new belt.


NOTE
After installing a new belt, run the engine for about 5 minutes and then recheck the belt tension.



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Fig. When removing ribbed belts, it's a good idea to mark the rotation direction of the belt if it is to be reused



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Fig. Ribbed style serpentine belt



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Fig. On 1.8L engines, use an open-end wrench to move the automatic tensioner. Align the tensioner and housing holes. Lock it in place using a suitable drift



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Fig. The tensioner assembly on the 1.8L engine shown retracted using a suitable hex tool



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Fig. On 1.8L engines, remove the fan pulley by counter holding it with a suitable drift, and loosen the fastener with an 8 mm hex wrench



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Fig. On 1.8L engines, loosen the air conditioner tensioner fasteners to allow for belt removal



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Fig. To tension the air conditioner belt on 1.8L engines, apply an 18 ft. lb. (25 Nm) load on the tensioner, and then tighten the fasteners



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Fig. On V6 engines, pivot the tensioner clockwise until the two holes are aligned and insert a suitable drift to keep it retracted

Key List for 93221g16:

Belt tensioner

Tensioning lever

Tensioning element



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Fig. Belt routing for the 1.8L engines



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Fig. Belt routing for the V6 engine



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Fig. Belt routing for the VR6 engine



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Fig. Belt routing for the 1995-96 Passat 2.0L ABA engine



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Fig. The 1.8L A/C belt is accessed from under the vehicle



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Fig. The belt tensioner on the 1.8L engine is held retracted using a suitable drift of hex key wrench



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Fig. On VR6 engines, an M8 bolt can be temporarily installed in the belt tensioning mechanism to relieve belt tension

 
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