Mercedes-Benz Cars 2000-05

Timing Chain Cover, Chain, Sprockets, & Seal

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Removal & Installation



  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Coolant
     
    Negative battery cable
     
    Engine undercover
     
    Serpentine belt
     
    Fan shroud and radiator
     
    Fan clutch and fan
     
    Crankshaft pulley
     
    Serpentine belt tensioner
     
    Vacuum pump
     
    Power steering pump
     
    Self-leveling suspension hydraulic pump
     
    Alternator
     

  4.  
  5. Cover the air conditioning condenser using a piece of sheet metal, plywood or plastic.

    Cylinder head cover and charge air pipe
     
    Oil dipstick tube
     
    Top Dead Center (TDC) sensor, marking its position
     

  6.  
  7. Support the engine and remove the engine mounts. Raise the engine to gain access.
  8.  
  9. Remove the timing cover bolts and carefully remove the cover from the engine. Be careful not to damage the oil pan and cylinder head gaskets.
  10.  

To install:

  1. Install or connect the following:

    Timing cover. Torque the bolts to 18 ft. lbs. (25 Nm).
     
    Engine mounts
     
    TDC sensor
     
    Oil dipstick tube
     
    Cylinder head cover and charge air pipe
     

  2.  
  3. Remove the air conditioning condenser guard

    Alternator
     
    Self-leveling suspension hydraulic pump
     
    Power steering pump
     
    Vacuum pump
     
    Serpentine belt tensioner
     
    Crankshaft pulley
     
    Fan clutch and fan
     
    Radiator and fan shroud
     
    Serpentine belt
     
    Engine undercover
     
    Negative battery cable
     
    Coolant
     

  4.  

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Cylinder head cover
     
    Injection nozzles
     
    Chain tensioner
     
    Fan and shroud
     
    Engine timing cover
     

  4.  
  5. Clamp the chain to the camshaft gear and cover the opening of the timing chain case.
  6.  
  7. Separate the chain with a chain breaker.
  8.  

To install:

  1. Attach a new timing chain to the old chain with a master link. Using a socket wrench on the crankshaft, slowly rotate the engine in the direction of normal rotation. Simultaneously, pull the old chain through until the master link is uppermost on the camshaft sprocket. Be sure to keep tension on the chain throughout this procedure.
  2.  


NOTE
Use only a rivet-type connecting link. Do not use connecting link that uses a retaining spring.

  1. Disconnect the old timing chain and connect the ends of the new chain with the master link. Insert the new connecting link from the rear so the lockwashers can be seen from the front.
  2.  
  3. Install the timing chain tensioner. Rotate the engine until the timing marks align. Check the valve timing.
  4.  
  5. Install or connect the following:

    Engine timing cover. Torque the bolts to 18 ft. lbs. (25 Nm).
     
    Cylinder head cover. Torque to 90 inch lbs. (10 Nm).
     
    Fan and fan shroud
     
    Injection nozzles
     
    Negative battery cable
     

  6.  

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Drain the cooling system and engine oil.
  6.  
  7. Remove or disconnect the following:

    Engine cover
     
    Engine cooling fan, fan clutch, and fan shroud
     

  8.  


NOTE
The fan clutch is equipped with right-hand thread.

  1. Place a guard plate behind the radiator/condenser to protect it from damage during removal and installation.

    Accessory drive belt and tensioner
     
    Cylinder head covers
     
    Coolant hoses
     
    A/C compressor and wire aside
     
    Oil pan
     
    Crankshaft pulley
     
    Timing chain tensioner
     
    Oil filter housing and heat exchanger
     
    Water pump pulley
     

  2.  


WARNING
The engine must not be rotated backward.

  1. Rotate the crankshaft clockwise to align the crankshaft timing marks at 40° After Top Dead Center (ATDC). Insure that the grooves in the camshafts (6 in the illustration) align with the cylinder head cover mating surface on the intake side of the cylinder heads.
  2.  


    Click image to see an enlarged view

    Fig. Camshaft timing marks



NOTE
The timing chain cover bolts are different lengths and diameters. Note their locations for installation.



Timing chain cover
 

  1. Lock the camshafts using the Camshaft Locking tools 112-589-00-32-00 and 112-589-01-32-00.

    Camshaft sprockets bolts
     
    Timing chain
     

  2.  

To install:

  1. Align the copper plated links of the timing chain with the marks on the camshaft sprockets, the crankshaft sprocket, and the balancer sprocket for the 3.2L and 3.7L engines. The 4.3L and 5.9L engines uses an idler sprocket in place of the balance shaft.
  2.  
  3. Install or connect the following:

    Camshaft sprockets along with the timing chain. Tighten the attaching bolts to 37 ft. lbs. (50 Nm) plus 90-100 degrees.
     

  4.  
  5. Clean the sealing surfaces and apply a bead of silicone sealant to the timing chain cover.
  6.  


NOTE
The cover must be installed within ten minutes after the sealant is applied.



Timing cover. Tighten the bolts to 15 ft. lbs. (20 Nm).
 


Click image to see an enlarged view

Fig. Exploded view of timing cover components- 3.2L and 3.7L engine shown; 4.3L and 5.0L engine similar

CT sensor
 
Timing chain tensioner
 
Generator
 
Crankshaft pulley and tighten the bolt to 148 ft. lbs., then tighten another 95 degrees
 
Air pump, if equipped
 
Air conditioning compressor and the power steering pump
 
Cylinder head covers
 
Oil pan
 
Accessory drive belt and tensioner
 
Upper and lower coolant hoses
 
Fan shroud, cooling fan, and fan clutch
 

  1. Fill the cooling system and the crankcase to the correct levels.

    Engine cover
     
    Negative battery cable
     

  2.  
  3. Read fault memory, encode the radio and normalize the power windows.
  4.  

 
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