Mazda Trucks 1987-1993 Repair Guide

Timing Belt and Sprockets

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The correct installation and adjustment of the camshaft drive belt is mandatory if the engine is to run properly. The camshaft controls the opening of the engine valves through coordination of the movement of the crankshaft and camshaft. When any given piston is on the intake stroke the corresponding intake valve must open to admit air/fuel mixture into the cylinder. When the same piston is on the compression and power strokes, both valves in that cylinder must be closed. When the piston is on the exhaust stroke, the exhaust valve for that cylinder must be open. If the opening and closing of the valves is not coordinated with the movements of the pistons, the engine will run vey poorly, if at all.

REMOVAL AND INSTALLATION



2.2L Engine

See Figures 1 through 8

  1. Disconnect the negative battery cable. Remove the accessory drive belts.
  2.  
  3. Remove the upper and the lower timing belt cover.
  4.  
  5. Turn the crankshaft to position the A mark on the camshaft pulley with the mark on the housing. Remove the crankshaft pulley mounting bolts and the pulley.
  6.  
  7. With brake pliers or another suitable tool, remove the timing belt tensioner spring. Now, remove the bolt from the tensioner and remove the tensioner.
  8.  
  9. Inspect the tensioner for bearing wear. It should rotate freely and smoothly. If not, replace it.
  10.  



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Fig. Fig. 1: Timing belt covers and timing belt removal/installation



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Fig. Fig. 2: Inspect the timing belt for damage



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Fig. Fig. 3: Timing belt sprocket matching marks

  1. Remove the timing belt and mark an arrow in the direction of rotation on the timing belt.
  2.  
  3. To remove the camshaft pulley, insert a T-wrench through the camshaft pulley onto a housing bolt, place another wrench on the pulley center bolt, hold the T-wrench securely and remove the pulley center bolt.
  4.  



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Fig. Fig. 4: Removing the timing belt sprocket lock bolt

  1. Pull the camshaft pulley from the camshaft. To remove the crankshaft pulley, remove the center bolt and the pulley.
  2.  
  3. Installation is the reverse of the removal procedure. Install the timing belt and be sure the timing mark on the timing belt pulley is aligned with the matching mark. Make sure that the mark (A) of the camshaft pulley is aligned with the timing mark. If it is not, turn the camshaft to align it.
  4.  



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Fig. Fig. 5: If installing the old timing belt, be sure to install it in the same rotational direction as before removal



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Fig. Fig. 6: Positioning the timing belt tensioner

  1. If using the old timing belt, be sure it is reinstalled in the same direction of previous rotation. Also make sure there is no oil, grease or dirt on the timing belt.
  2.  
  3. Install the timing belt tensioner and spring.
  4.  
  5. Make sure the belt remains engaged at all three sprockets and that crankshaft and camshaft sprockets are properly in time. Locate the tensioner on its swivel pin with the slot through which the mounting bolt passes centered over the bolt hole. Install the bolt, but do not tighten it.
  6.  
  7. Install the tensioner spring. Temporarily secure it as the spring is fully extended.
  8.  



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Fig. Fig. 7: Tighten the timing belt tensioner lock bolt



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Fig. Fig. 8: Timing belt deflection checking point

  1. Loosen the tensioner lock bolt. Turn the crankshaft twice in the diretion of rotation. Align the timing marks. Tighten the timing belt tensioner lock bolt to 28-38 ft. lbs. (38-52 Nm). Check the timing belt tension. The timing belt deflection should be 11-13mm (0.433-0.510 in.) at 22 lbs.
  2.  

3.0L Engine

See Figures 9 through 23



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Fig. Fig. 9: Remove the upper idler pulley



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Fig. Fig. 10: Location of the timing marks on the timing belt cover



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Fig. Fig. 11: Before removing the timing belt, line up the timing marks on the crankshaft sprocket and the engine block ...



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Fig. Fig. 12: ... the right side camshaft sprocket and the mark on the cylinder head ...



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Fig. Fig. 13: ... and the left side camshaft sprocket and the cylinder head



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Fig. Fig. 14: Mark the direction of rotation on the timing belt if installing the same belt



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Fig. Fig. 15: Rmove the timing belt



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Fig. Fig. 16: Remove the timing belt tensioner from the front of the engine



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Fig. Fig. 17: Remove the cranshaft sprocket by pulling straight off of the crankshaft



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Fig. Fig. 18: After removing the crankshaft sprocket, remove the woodruff ke. Be careful not to lose this

  1. Disconnect the negative battery cable, and drain the cooling system.
  2.  
  3. Remove the timing belt covers.
  4.  
  5. Remove the upper idler pulley.
  6.  
  7. Turn the crankshaft to align the matching marks on the sprockets. If the timing belt is to be reused, make an arrow on the belt to indicate rotation direction.
  8.  
  9. Remove the timing belt and automatic tensioner.
  10.  
  11. Using SST 49 H012 010 tool or its equivalent, loosen and remove the camshaft sprocket lock bolts. Remove the camshaft sprockets.
  12.  
  13. Using a suitable puller, remove the crankshaft sprocket.
  14.  

To install:
  1. Install the crankshaft sprocket to the crankshaft.
  2.  
  3. Install the camshaft sprockets with the lock bolts and torque the bolts to 52-59 ft. lbs. (71-80 Nm).
  4.  



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Fig. Fig. 19: Place the washer on the tensioner allowing the plug on the tensioner to fit through the hole in the washer



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Fig. Fig. 20: Mount the tensioner assembly and washer in the bench vise as shown



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Fig. Fig. 21: When compressing the tensioner and plunger, be sure to line up the holes of the plunger to the hole in the tensioner body



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Fig. Fig. 22: Once the plunger and tensioner holes are aligned ...



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Fig. Fig. 23: ... place a small hex key into the holes to keep the plunger compressed

  1. Set a plane washer at the bottom of the tensioner body to prevent damage to the body plug. Press in the tensioner rod slowly, using a press or a vise.
  2.  

Do not press the tensioner rod more than 2200 lbs. (9800N).

  1. Insert a pin to hold the tensioner rod in the body. Install the automatic tensioner and tighten the mounting bolts to 14-19 ft. lbs. (19-25 Nm).
  2.  
  3. Install the crankshaft pulley lock bolt and loosely tighten. Check the alignment of the matching marks on the sprockets.
  4.  
  5. With the upper idler pulley removed, install the timing belt, making sure there is no slack between the crankshaft and camshaft sprockets. If the timing belt is being reused, it must be installed in the same direction of rotation.
  6.  
  7. Install the upper idler pulley and tighten the attaching bolt to 27-38 ft. lbs. (37-52 Nm).
  8.  
  9. Turn the crankshaft twice in the direction of rotation and align the matching marks. If the marks do not align, repeat the previous three steps.
  10.  
  11. Remove the pin from the automatic tensioner. Turn the crankshaft twice and align the matching marks. Make sure the marks are aligned.
  12.  
  13. Check the timing belt deflection. The deflection should be 0.20-0.28 in. (5-7mm). Do not apply tension other than that of the automatic tensioner.
  14.  
  15. If the deflection is not correct, repeat the previous three steps.
  16.  
  17. Remove the crankshaft pulley lock bolt.
  18.  
  19. Install the timing belt cover, along with the related components.
  20.  
  21. Reinstall the crankshaft pulley and torque the lock bolt to 116-123 ft. lbs. (37-52 Nm).
  22.  
  23. Fill and bleed the cooling system.
  24.  
  25. Run the engine and check for leaks and proper operation. Check the idle speed and the ignition timing.
  26.  

 
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