Mitsubishi Pick-ups and Montero 1983-1995 Repair Guide

Camshafts and Bearings

Print

REMOVAL & INSTALLATION



2.0L and 2.4L Engines

See Figure 1

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the distributor following procedures outlined in General Information & Maintenance .
  4.  
  5. Remove the valve cover and remove the timing belt assembly following procedures described in this section.
  6.  
  7. Remove the rocker arm assembly following procedures given in this section.
  8.  
  9. Lift the camshaft off the cylinder head. Place it on a padded surface in a protected area. Inspect the camshaft.
  10.  



Click image to see an enlarged view

Fig. Fig. 1: Camshaft assembly-2.0L engines

To install:
  1. Thoroughly lubricate the bearing journals on the camshaft and the bearing seats in the head with clean engine oil. Place the camshaft in position on the head.
  2.  
  3. Liberally coat the bearing caps with clean engine oil. Install the rocker shaft and bearing cap assembly. Tighten the bearing cap assembly bolts evenly in two or three steps; final torque should be 15 ft. lbs. (20 Nm).
  4.  
  5. Reinstall the camshaft sprocket and timing belt.
  6.  
  7. Install the valve cover.
  8.  
  9. Install the distributor. Connect the negative battery cable.
  10.  

2.3L Diesel Engine

See Figures 2, 3 and 4

  1. Disconnect the negative battery cable.
  2.  
  3. Label and disconnect the breather hose and any vacuum hoses running around or across the valve cover.
  4.  
  5. Remove the valve cover.
  6.  
  7. Remove the upper timing cover.
  8.  
  9. Using a wrench on the center bolt, turn the crankshaft clockwise until all the timing marks line up. This positions the No.1 piston on TDC/compression. Both valves for No.1 cylinder are closed.
  10.  
  11. Without disturbing the engine position, loosen the center bolt on the camshaft sprocket.
  12.  
  13. Loosen the retaining bolts on the timing belt adjuster. Move the adjuster towards the water pump and temporarily tighten the bolts, holding the adjustor in the slack position.
  14.  
  15. Remove the sprocket with the timing belt attached. Note the relative position of the camshaft to the camshaft sprocket. Keep upward tension on the sprocket and belt.
  16.  
  17. Remove the rocker assembly, following directions outlined earlier in this section.
  18.  
  19. Remove the camshaft bearing caps, keeping them in order. Remove the front camshaft oil seal and discard.
  20.  
  21. Lift the camshaft off the cylinder head. Place it on a padded surface in a protected area. Inspect the camshaft.
  22.  



Click image to see an enlarged view

Fig. Fig. 2: Find the camshaft end-play by subtracting the measurement of A from the measurement of B-2.3L Diesel Engines



Click image to see an enlarged view

Fig. Fig. 3: Install the camshaft bearing caps in the order shown-2.3L Diesel Engines



Click image to see an enlarged view

Fig. Fig. 4: Use the oil seal installing tool MD998381-01 and a hammer to insert the new oil seal-2.3L Diesel Engines

To install:
  1. Thoroughly lubricate the bearing journals on the camshaft and the bearing seats in the head with clean engine oil. Place the camshaft in position on the head.
  2.  
  3. Liberally coat the bearing caps with clean engine oil. Install the bearing caps. Tighten the bolts evenly in two or three steps; final torque should be 15 ft. lbs. (20 Nm).
  4.  
  5. After the camshaft bearing caps are in place and tightened to the correct amount of torque, drive the new oil seal onto the front end of the camshaft with a camshaft oil seal installer (part MD998381-01) with a hammer until the oil seal is fully seated.
  6.  
  7. Rotate the camshaft until it is in its original position (do NOT rotate the timing belt assembly) and reinstall the camshaft sprocket and timing belt. Tighten the center bolt to 52 ft. lbs. (70 Nm). Make certain the sprocket lines up on the guide pin in the end of the camshaft.
  8.  
  9. Double check the alignment of all the timing marks, particularly the camshaft sprocket.
  10.  
  11. Loosen the bolts on the tensioner, allowing the tensioner to move against the belt under its spring tension.
  12.  


WARNING
Do not assist the tensioner by pushing on it-let the spring do the work.

  1. Use a wrench on the crankshaft bolt to turn the engine clockwise until the camshaft sprocket has moved two teeth out of position. Note that this is done with the belt adjustor loose. Be certain to turn the engine smoothly and only by the specified amount; the motion is necessary to correctly tension the belt.
  2.  
  3. Tighten the upper bolt on the tensioner, then tighten the lower bolt. Correct torque for each bolt is 18 ft. lbs. (25 Nm). If the order of tightening is not followed the tensioner will turn, allowing the belt to receive incorrect tension.
  4.  
  5. Turn the engine in the reverse (counterclockwise) direction until all the timing mark align.
  6.  
  7. Push on the belt midway between the cam sprocket and the injection pump; correct deflection is 0.16-0.20 in. (4-5mm).
  8.  
  9. Install the valve cover and gasket.
  10.  
  11. Reconnect the vacuum and breather hoses.
  12.  

2.6L Engine

See Figure 5

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the distributor.
  4.  
  5. Remove the valve cover by adhering to the previously described directions in this section.
  6.  
  7. Remove the rocker arm assembly following procedures given in this section.
  8.  
  9. Remove the camshaft sprocket along with the timing chain. Secure these two pieces together with wire or string. Set these two down on the lower chain stays.
  10.  
  11. Remove the rear bearing cap bolts and the cap. These are not associated with the rocker shaft assembly.
  12.  
  13. Lift the camshaft off the cylinder head. Place it on a padded surface in a protected area. Refer to the inspection section following for correct procedures.
  14.  



Click image to see an enlarged view

Fig. Fig. 5: Camshaft assembly-2.6L engines

To install:
  1. Thoroughly lubricate the bearing journals on the camshaft and the bearing seats in the head with clean engine oil. Place the camshaft in position on the head. Be careful not to damage the camshaft journals during installation.
  2.  
  3. Apply a sealer to the outside diameter of the circular seal for the rear bearing and install it in the head with one side directly in contact with the rear of the camshaft. The packing will end up under the rearmost portion of the rear bearing cap.
  4.  
  5. Install the rocker shaft/bearing cap assembly. tighten retaining bolts in steps working from the center out to 15 ft. lbs. (20 Nm).
  6.  
  7. Reinstall the cam sprocket and chain to the camshaft.
  8.  
  9. Inspect the semi-circular seal that goes in the front of the timing chain cover. Seal the top with an adhesive such as 3M® Adhesive 8001 or equivalent.
  10.  
  11. Install the rocker cover.
  12.  
  13. Install the distributor. Connect the negative battery cable.
  14.  
  15. Start the engine and allow it to idle until the temperature gauge indicates normal operating temperature. Check to make sure that it is running correctly and not leaking.
  16.  

3.0L Engines

See Figures 6, 7, 8, 9, 10, 11 and 12

  1. Disconnect the negative battery cable.
  2.  
  3. Follow the directions for timing belt removal, located in this section.
  4.  
  5. Remove the two camshaft sprockets using the special Mitsubishi tools (MB990767-01 and MIT308239).
  6.  
  7. Remove the cooling fan stay, the alternator bracket stay and the alternator bracket.
  8.  
  9. Remove the oil filler hose filter and hose.
  10.  
  11. Remove the rocker arm covers and the old gaskets. Discard the gaskets as new ones will be needed for installation.
  12.  
  13. Remove the circular packing from the rear of the camshaft bore, and the oil seal from the front of the camshaft bore. Discard both, as new ones will be needed for installation.
  14.  
  15. Remove the distributor adapter and O-ring. Discard the old O-ring, a new one will be needed for installation.
  16.  
  17. Remove the rocker arm shaft assemblies.
    1. Install the special tools (MD998443-01) to the rocker arms to hold the lash adjusters.
    2.  
    3. Loosen the camshaft bearing cap bolt. Do not remove the bolts from the cap.
    4.  
    5. Remove the rocker arms, shaft and bearing cap as an assembly.
    6.  

  18.  
  19. Lift the camshaft off the cylinder head. Place it on a padded surface in a protected area. Refer to the inspection section following for correct procedures.
  20.  



Click image to see an enlarged view

Fig. Fig. 6: Preliminary camshaft removal components-3.0L Engines



Click image to see an enlarged view

Fig. Fig. 7: Use these two special tools to remove the camshaft sprockets-3.0L Engines



Click image to see an enlarged view

Fig. Fig. 8: Camshaft assembly-3.0L Engines



Click image to see an enlarged view

Fig. Fig. 9: Match the arrow marks on the rocker arm assemblies with the directional arrows on the heads-3.0L Engines



Click image to see an enlarged view

Fig. Fig. 10: Use the special tool (MD998713-01) to install the camshaft oil seal-3.0L Engines



Click image to see an enlarged view

Fig. Fig. 11: Use the special tool (MD998714-01) and the washer to install the circular packing-3.0L Engines



Click image to see an enlarged view

Fig. Fig. 12: Apply the sealant to the specified areas-3.0L Engines

To install:
  1. Thoroughly lubricate the bearing journals on the camshaft and the bearing seats in the head with clean engine oil. Place the camshaft in position on the head. Be careful not to damage the camshaft journals during installation.
  2.  
  3. Install the rocker arm shaft assembly (if the rocker arm shaft assembly was disassembled, refer to the rocker arm removal directions, outlined previously in this section).
    1. Apply a minimum amount of the specified sealant (3M® Nut Locking No. 4171 or equivalent) on the four places of the cylinder head.
    2.  

  4.  

Be sure the sealing agent does not swell out onto the camshaft journal surface of the cylinder heads. If it swells out, immediately wipe it off before it can dry.

    1. Install the rocker arms, shafts and bearing caps such that the arrow mark on the bearing cap faces in the same direction as the arrow mark on the cylinder heads.
    2.  
    3. Tighten the bearing cap bolts to the specified torque.
    4.  
    5. Remove the special tools from all of the rocker arms.
    6.  


  1. Install the distributor adapter with a new O-ring.
  2.  
  3. Install the new camshaft oil seal. Use the special Mitsubishi tool (MD998713-01 or equivalent) to install the new camshaft oil seal. Coat the rubber seal edge with a layer of clean engine oil before installation.
  4.  
  5. Install the rear circular packing.
    1. Install a 0.052-0.059 in. (1.3-1.5mm) thick spacer to the special tool (MD998714-01) and drive the circular packing in.
    2.  

  6.  

Use of the tool (MD724328) spacer for transmissions is recommended.


CAUTION
The packing is overdriven if no spacer is fitted to the special tool.

  1. Install the rocker arm cover with the old gasket, if the old gasket is not damaged (for more information-refer to the removal instructions for rocker arm covers in this section). Apply specified sealant (3M® ATD Part No. 8660 or equivalent) on the areas specified in the illustration.
  2.  
  3. Install the oil filler tube and oil filler filter.
  4.  
  5. Install the alternator bracket, the alternator bracket stay and the cooling fan stay.
  6.  
  7. Install the camshaft sprockets using the special tools that were used upon removal.
  8.  
  9. Follow the timing belt installation instructions and install all equipment taken off the engine during removal.
  10.  

3.5L DOHC Engines

See Figures 13 through 19

  1. Follow the directions for intake manifold removal and installation outlined previously in this section.
  2.  
  3. Remove the timing belts by following the procedures described previously in this section.
  4.  
  5. Remove the center covers on the rocker arm covers.
  6.  
  7. Remove the three (3) ignition coils and their respective spark plug wires. Label the wires for ease of installation.
  8.  
  9. Remove the rocker arm covers from the heads.
  10.  
  11. Remove the four (4) camshaft sprockets. Use a wrench to hold the hexagonal part of the camshaft to prevent the crankshaft from turning, and then loosen the camshaft sprocket bolt.
  12.  


CAUTION
Do not hold the camshaft sprocket with a tool, or a damaged sprocket could be the result.

  1. Remove the camshaft bearing caps in this order: front, rear, No. 2, No. 4, No. 3.
  2.  
  3. Lift the camshafts off the cylinder head. Place them on a padded surface in a protected area. Refer to the inspection section following for correct procedures.
  4.  
  5. Remove the rocker arms and lash adjusters, for service of these two parts refer to the procedures described previously in this section.
  6.  



Click image to see an enlarged view

Fig. Fig. 13: Preliminary camshaft removal components-3.5L Engines



Click image to see an enlarged view

Fig. Fig. 14: Use these two wrenches to remove the camshaft sprockets, make sure to grip the camshaft hexagonal section-3.5L Engines



Click image to see an enlarged view

Fig. Fig. 15: Camshaft assembly-3.5L Engines



Click image to see an enlarged view

Fig. Fig. 16: Before installation check the identification stamped on the camshafts' hexagonal section-3.5L Engines



Click image to see an enlarged view

Fig. Fig. 17: Position the camshafts so that their dowel pins are in the positions shown-3.5L Engines



Click image to see an enlarged view

Fig. Fig. 18: The bearing caps have three (3) identification marks stamped on them: the direction of installation, the number of the cap, and whether it is for the intake or exhaust side of the head-3.5L Engines



Click image to see an enlarged view

Fig. Fig. 19: Install the camshaft oil seal with the special Mitsubishi tool shown-3.5L Engines

To install:
  1. Install the rocker arms on the valve stems and the lash adjusters.
  2.  
  3. Thoroughly lubricate the bearing journals on the camshaft and the bearing seats in the head with clean engine oil. Place the camshaft carefully in position on the head. Be careful not to damage the camshaft journals during installation.
    1. Make sure the crankshaft is still at top dead center on No. 1 cylinder.
    2.  
    3. Check to make sure that the rocker arm is installed correctly on the lash adjuster and valve.
    4.  
    5. Install the camshaft while noting the identification mark (stamped on the hexagonal section).
    6.  
    7. Install the camshafts with their dowel pins positioned as shown in the illustration.
    8.  

  4.  
  5. Loosely install the bearing caps onto the head. Install the bearing caps according to the identification mark and cap number. No. 2, 3 and 4 bearing caps have the front mark stamped on them. Install these caps with the front mark pointing in the same direction as that on the cylinder head. Each cap will have either an "I" ,for intake, or an "E", for exhaust.
  6.  
  7. Gradually tighten the bearing caps in two or three steps. In the final step, tighten to the specified torque.
  8.  
  9. Install the camshaft oil seals into the front camshaft bearing cap. Use the special tool (MD998761-01) to correctly install the seal. Make sure to apply a thin film of oil to the rubber sealing edge of the seal.
  10.  
  11. Install the circular packing into the rear camshaft bearing cap. Use the special Mitsubishi tool (MD998762-01) to install this packing correctly.
  12.  
  13. Install the four (4) camshaft sprockets in the same manner as they were removed.
  14.  
  15. Install the rocker covers, using a new gasket if the old gasket is damaged in any way. Apply 3M® ADT Part No. 8660 or equivalent sealant to the specified areas.
  16.  
  17. Reinstall the ignition coils and their spark plug wires. Make sure the wires are routed as they were when removed.
  18.  
  19. Fasten the center covers back onto the rocker arm covers.
  20.  
  21. Reinstall and adjust the timing belts using the previous directions.
  22.  
  23. Install the intake manifold by using the procedures used upon disassembly.
  24.  
  25. Start the vehicle and check for leaks, noises or other irregularities.
  26.  

INSPECTION AND MEASUREMENT



The end-play or thrust clearance of the camshaft(s) must be measured with the camshaft installed in the head. In most cases it may be checked before removal or after reinstallation. To check the end-play, mount a dial indicator accurate to ten one-thousandths (four decimal places) on the end of the block, so that the tip bears on the end of the camshaft. The timing belt or timing chain must be removed. On some motors, it will be necessary to remove the sprockets for unobstructed access to the camshaft. Set the scale on the dial indicator to zero. Using a prytool, gently lever the camshaft fore-and-aft in its mounts. Record the amount of deflection shown on the gauge and compare this number to the Camshaft Specifications Chart.

If the camshaft has a removable thrust case, the case must be reinstalled to the end of the camshaft and the bolt tightened. Check the end-play with a feeler gauge. If the end-play is excessive, replace the thrust case with a new one and recheck the clearance. If the end-play is still excessive, replace the camshaft.

Excessive end-play may indicate either a worn camshaft or a worn head; the worn camshaft is most likely and much cheaper to replace. Chances are good that if the camshaft is worn in this dimension (axial), substantial wear will show up in other measurements.

Using a micrometer or Vernier caliper, measure the diameter of all the journals and the height of all the lobes. Record the readings and compare them to the Camshaft Specifications Chart in the beginning of this Section. Any measurement beyond the stated limits indicates wear and the camshaft must be replaced.

Lobe wear is generally accompanied by scoring or visible metal damage on the lobes. Overhead camshaft engines are very sensitive to proper lubrication with clean, fresh oil.

If a new camshaft is required, order new rockers to accompany it so that there are two new surfaces in contact.

The clearance between the camshaft and its journals (bearings) must also be measured. The amount of space between the camshaft and its bearings is the oil clearance; less space means less oil and more wear. Excessive play will allow the camshaft to hammer the bearing and cause wear. Clean the camshaft, the journals and the bearing caps of any remaining oil and place the camshaft in position on the head. Lay a piece of compressible gauging material (Plastigage® or similar) on top of each journal on the cam.

Install the bearing caps in their correct order and install the rocker assembly. Tighten the bolts in three passes to the correct torque.


WARNING
Do not turn the camshaft with the gauging material installed.

Remove the rocker assembly and measure the gauging material at its widest point by comparing it to the scale provided with the package. Compare these measurements to the Camshaft Specifications Chart. Any measurement beyond specifications indicates wear. If you have already measured the cam (or replaced it) and determined it to be usable, excess bearing clearance indicates the need for a new head due to wear of the journals.

Remove the camshaft from the head and remove all traces of the gauging material. Check carefully for any small pieces clinging to contact faces.

After a careful cleaning, coat the camshaft and bearing surfaces with clean engine oil and continue reassembly.

 
label.common.footer.alt.autozoneLogo