Chrysler Full-Size Trucks 1967-1988 Repair Guide

Cylinder Head

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REMOVAL & INSTALLATION



6-198 and 6-225 Engines

See Figures 1 and 2

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove the air cleaner and the fuel line from the carburetor.
  6.  
  7. Disconnect the accelerator linkage.
  8.  



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Fig. Fig. 1: L6-225 cylinder head assembly

  1. Remove the vacuum advance line from between the carburetor and the distributor.
  2.  
  3. Disconnect the cables from the spark plugs, then remove the plugs.
  4.  
  5. Disconnect the heater hose and the clamp which secures the by-pass hose.
  6.  
  7. Disconnect the water temperature sending unit.
  8.  
  9. Disconnect the exhaust pipe at the exhaust manifold flange. Disconnect the diverter valve line (if equipped) from the intake manifold and remove the air tube assembly from the cylinder head.
  10.  
  11. Remove the intake and exhaust manifolds along with the carburetor as an assembly.
  12.  
  13. Remove the closed ventilation systems, the evaporative control system (if so equipped), and the valve cover.
  14.  
  15. Remove the rocker arm and shaft assembly.
  16.  
  17. Remove the pushrods and keep them in order to ensure installation in their original locations.
  18.  
  19. Remove the head bolts then remove the cylinder head.
  20.  

To install:
  1. Clean all of the gasket surfaces of the engine block and the cylinder head, then install the spark plugs.
  2.  

If your truck hasn't had a tune-up in a while this is now a good opportunity to do one.

  1. Inspect all surfaces with a straightedge. If warpage is indicated, measure the amount. This amount must not exceed 0.00075 times the span length in any direction. For example, if a 12 inch span is 0.004 in. (0.10mm) warped, the maximum allowable is 12 x 0.00075 in. (0.019mm) = 0.009 in. (0.22mm). In this case, the head is within limits. If warpage exceeds the specified limits, either replace the head or lightly machine the head gasket surface.
  2.  

To install:
  1. Coat a new cylinder head gasket with sealer, install the gasket and cylinder head.
  2.  
  3. Install the cylinder head bolts. Torque the cylinder head bolts to 35 ft. lbs. (47 Nm) in the sequence indicated in the illustration. Repeat this sequence to re-torque all the head bolts to 70 ft. lbs. (95 Nm).
  4.  



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Fig. Fig. 2: 6-198, 6-225 cylinder head torque sequence

  1. Install the pushrods in their original locations.
  2.  
  3. Install the rocker arm and shaft assembly.
  4.  
  5. Install valve cover, the closed ventilation systems, and the evaporative control system.
  6.  
  7. Install the intake and exhaust manifolds along with the carburetor as an assembly.
  8.  

When installing the intake and exhaust manifold assembly, loosen the 3 bolts which secure the intake manifold to the exhaust manifold to maintain proper alignment. After installation, torque the 3 bolts in this sequence: inner bolt, then outer bolts. Refer to the manifold section, later in this section, for the proper tightening sequence. Check the valve adjustment.

  1. Connect the exhaust pipe at the exhaust manifold flange. Connect the diverter valve line (if equipped) at the intake manifold and install the air tube assembly from the cylinder head.
  2.  
  3. Connect the water temperature sending unit.
  4.  
  5. Connect the heater hose and the clamp which secures the by-pass hose.
  6.  
  7. Connect the cables at the spark plugs.
  8.  
  9. Install the vacuum advance line between the carburetor and the distributor.
  10.  
  11. Connect the accelerator linkage.
  12.  
  13. Install the air cleaner and the fuel line at the carburetor.
  14.  
  15. Fill the cooling system and connect the battery cable.
  16.  

6-251 Engine

See Figure 3

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Remove the carburetor.
  2.  
  3. Disconnect any hoses, lines and wires attached to the head.
  4.  
  5. Remove the spark plugs.
  6.  
  7. Remove the bolts in reverse of the tightening sequence. See the illustration.
  8.  



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Fig. Fig. 3: 6-251 cylinder head torque sequence

  1. Lift off the head.
  2.  
  3. Inspect the head for signs of damage.
  4.  
  5. Clean the head thoroughly and check it for warpage. Lay a good straightedge across the head, diagonally and lengthwise. If the head is off by more than 0.024 in. (0.60mm) lengthwise or 0.006 in. (0.15mm) crosswise, it must be machined. Maximum material removal is 0.20 in. (5mm).
  6.  

If your truck hasn't had a tune-up in a while this is now a good opportunity to do one.

  1. When installing the head, always use a new gasket coated on both sides with sealer. Following the tightening sequence shown when tightening the head bolts. Torque the bolts to 70 ft. lbs. (95 Nm). Run the engine to normal operating temperature and retorque the bolts with the engine hot to 70 ft. lbs. (95 Nm). After 20 hours or 500 miles of operation, whichever comes first, retorque the bolts to 70 ft. lbs. (95 Nm).
  2.  

V6 and V8 Gasoline Engines

See Figures 4 through 12

  1. Drain the cooling system and disconnect the battery ground cable.
  2.  
  3. Remove the alternator, air cleaner, and fuel line.
  4.  
  5. Disconnect the accelerator linkage.
  6.  
  7. Remove the vacuum advance line from between the carburetor and the distributor. On trucks with the 360 cu. in. engine, remove the battery.
  8.  
  9. Remove the distributor cap and wires as an assembly.
  10.  
  11. Disconnect the coil wires, water temperature sending unit, heater hoses, and bypass hose. On the 360 and 413, remove the distributor and governor.
  12.  
  13. Remove the closed ventilation system, the evaporative control system (if so equipped), and the valve covers.
  14.  
  15. Remove the intake manifold, ignition coil, and carburetor as an assembly.
  16.  
  17. Remove the exhaust manifolds. On 360 and 413, tag the center bolts.
  18.  
  19. Remove the tappet chamber cover. Remove the rocker and shaft assemblies.
  20.  
  21. Remove the pushrods and keep them in order to ensure installation in their original locations. On the 360 and 413, remove the water pump-to-heads bolts.
  22.  



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Fig. Fig. 4: Remove all the pushrods



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Fig. Fig. 5: V8-Make sure you keep the pushrods in order for installation purposes

  1. Remove the head bolts from each cylinder head and remove the cylinder heads.
  2.  



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Fig. Fig. 6: Carefully pry the cylinder head up to loosen and remove.



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Fig. Fig. 7: Remove the cylinder head; careful, its heavy

  1. Clean all the gasket surfaces of the engine block and the cylinder heads.
  2.  



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Fig. Fig. 8: Discard the old cylinder head gasket



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Fig. Fig. 9: Scrape all gasket material from the cylinder head surface before installing a new gasket-note you should place a clean rag in each of the cylinders to keep debris out

  1. Inspect all surfaces with a straightedge. If warpage is indicated, measure the amount. This measurement must not exceed 0.00075 times the span length in any direction. For example, if a 12 in. span is 0.004 in. (0.10mm) warped, the maximum allowable difference is 12 x 0.00075 (0.019mm) = 0.009 in. (0.22mm) In this case, the head is within limits. If the warpage exceeds the specified limits, either replace the head or lightly machine the head gasket surface.
  2.  
  3. Coat new cylinder head gaskets with sealer, install the gaskets and install the cylinder heads.
  4.  

The number and size of the cooling passages in the 318 heads were changed during the 1976 model year. The new type gasket can be used with the old heads, but the old type gasket can't be used with the new heads.

  1. Install the cylinder head bolts. Torque the cylinder head bolts to 50 ft. lbs. (68 Nm) in the sequence indicated. Repeat this sequence to re-torque all the cylinder head bolts to specifications.
  2.  



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Fig. Fig. 10: 8-318, 360 cylinder head bolt torque sequence



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Fig. Fig. 11: 8-383, 400, 413 and 440 cylinder head bolt torque sequence



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Fig. Fig. 12: V6-238 cylinder head bolt torque sequence

  1. Install the pushrods.
  2.  
  3. On the 360 and 413, install the water pump-to-heads bolts.
  4.  
  5. Install the rocker and shaft assemblies. Install the tappet chamber cover.
  6.  
  7. Install the exhaust manifolds.
  8.  
  9. Install the intake manifold, ignition coil, and carburetor as an assembly.
  10.  
  11. Install the closed ventilation system, the evaporative control system (if so equipped), and the valve covers.
  12.  
  13. Connect the coil wires, water temperature sending unit, heater hoses, and bypass hose. On the 360 and 413, install the distributor and governor.
  14.  

If your truck hasn't had a tune-up in a while this is a good opportunity to do one.

  1. Install the distributor cap and wires as an assembly.
  2.  
  3. Install the vacuum advance line between the carburetor and the distributor. On trucks with the 360 cu. in. engine, install the battery.
  4.  
  5. Connect the accelerator linkage.
  6.  
  7. Install the alternator, air cleaner, and fuel line.
  8.  
  9. Fill the cooling system and connect the battery ground cable.
  10.  

Diesel Engines
  1. Remove the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner.
  4.  
  5. Disconnect the hoses from the fuel filter at the transfer pump and the injection pump. Drain the filter and remove it from the manifold.
  6.  
  7. Remove the manifold nuts and air cleaner mounting bracket attaching nuts.
  8.  
  9. Disconnect the injection lines for cylinders 3 and 6 from the injection pump.
  10.  
  11. Remove the intake manifold and gaskets from the head.
  12.  
  13. Push the exhaust manifold shield to one side.
  14.  
  15. Remove the heater hose and the bypass hose.
  16.  
  17. Remove the thermostat housing and the upper radiator hose from the water manifold. Remove the spray gasket.
  18.  
  19. Disconnect the temperature sending unit wire.
  20.  
  21. Disconnect the fuel line mounting brackets from the cylinder head and push the fuel lines aside.
  22.  
  23. Remove the three exhaust manifold bridges.
  24.  
  25. Remove the water manifold and gasket from the cylinder head.
  26.  
  27. Raise the truck and support with jackstands.
  28.  
  29. Disconnect the exhaust pipe from the exhaust manifold.
  30.  
  31. Lower the truck. Remove the exhaust manifold, heat shield and gasket.
  32.  
  33. Disconnect and remove the wire from each glow plug.
  34.  
  35. Remove the injection lines from the injection pump.
  36.  
  37. Disconnect the fuel injection line from the head. Remove the bracket and the ground strap.
  38.  
  39. Disconnect the alternator bracket and the engine lifting fixture. Push them aside.
  40.  
  41. Remove the cylinder head cover and the gasket.
  42.  
  43. Loosen and remove the cylinder head bolts in the sequence illustrated.
  44.  
  45. Lift out the rocker arm and shaft assembly.
  46.  
  47. Remove the pushrods, keeping them in order. The pushrods MUST be installed in their original locations.
  48.  
  49. Disconnect and remove the glow plug buss bar.
  50.  
  51. Remove the six glow plugs from the cylinder head.
  52.  
  53. Remove the cylinder head. Check the head for cracks, damage or evidence of water leaks. Clean all the oil, grease, scale, sealant and carbon from the head. Thoroughly clean the gasket surfaces. Also check each combustion chamber jet for cracks or melting. If a jet is cracked or melted, remove it with a pushrod inserted through a glow plug bore.
  54.  

To install:
  1. Inspect all cylinder head surfaces with a straightedge. Out-of-flatness must not exceed 0.010 in. (0.25mm). If it does, a surface grinder must be used to bring the head to an out-of-flatness of less than 0.006 in. (0.15mm).
  2.  
  3. Install the glow plugs in the head. Tighten them firmly.
  4.  
  5. Install the injectors, injector tubes and the injector holders in the head. Tighten the nozzle holder attaching nuts to 37 ft. lbs. (50 Nm).
  6.  
  7. Coat the new gasket lightly with sealer. Place the gasket on the block and place the cylinder head over the dowels.
  8.  
  9. Install the cylinder head bolts and tighten them in the sequence to 90 ft. lbs. (122 Nm). Do not install the head bolts which retain the rocker shaft assembly.
  10.  
  11. Install the pushrods in their original locations.
  12.  
  13. Install the rocker arm and shaft assembly. Tighten the mounting bolts to 90 ft. lbs. (122 Nm).
  14.  
  15. Adjust the valve clearance to 0.012 in. (0.30mm) at top dead center of each cylinder compression stroke.
  16.  
  17. Install the cylinder head cover and gasket.
  18.  
  19. Install the alternator bracket and the engine lifting fixture.
  20.  
  21. Connect the fuel lines to the injection pump (except nos. 3 and 6). Install the bracket and the group strap.
  22.  
  23. Install the fuel line to the transfer pump.
  24.  
  25. Install the exhaust manifold and the heat shield assembly, using a new gasket.
  26.  
  27. Raise the truck and support it safely. Attach the exhaust pipe to the exhaust manifold.
  28.  
  29. Lower the truck and install the water manifold on the head using a new gasket.
  30.  
  31. Install the three exhaust manifold bridges.
  32.  
  33. Install the fuel lines in the bracket.
  34.  
  35. Connect the temperature sending unit wire.
  36.  
  37. Using a new gasket, install the thermostat housing. Attach the upper radiator hose to the thermostat housing.
  38.  
  39. Install the bypass and heater hoses.
  40.  
  41. Install the exhaust manifold heat shield and the exhaust manifold.
  42.  
  43. Using a new gasket and spray shield, install the air intake manifold.
  44.  
  45. Connect the injection lines from cylinders 3 and 6 to the injection pump.
  46.  
  47. Install the fuel filter to the back of the manifold.
  48.  
  49. Connect the fuel hoses.
  50.  
  51. Install the air cleaner bracket and install the air cleaner.
  52.  
  53. Connect the negative battery cable, and finally, fill the cooling system.
  54.  

INSPECTION



See Figures 13, 14 and 15

  1. With the valves installed to protect the valve seats, remove deposits from the combustion chambers and valve heads with a scraper and a wire brush. Be careful not to damage the cylinder head gasket surface. After the valves are removed, clean the valve guide bores with a guide cleaning tool. Use cleaning solvent to remove the dirt, grease and other deposits. Clean all the retaining bolt holes, and make sure all the oil passages are clear.
  2.  



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Fig. Fig. 13: With the valves removed, a wire wheel may be used to clean the combustion chambers of carbon deposits



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Fig. Fig. 14: 6-198, 6-225 valve assemblies

  1. Remove all deposits from the valves with a fine wire brush or buffing wheel.
  2.  
  3. Inspect the cylinder heads for cracks or excessively burned areas in the exhaust outlet ports.
  4.  
  5. Check the cylinder head for cracks and inspect the gasket surface for burrs and nicks. Replace the head if it is cracked.
  6.  
  7. On cylinder heads that incorporate valve seat inserts, check the inserts for excessive wear, cracks, or looseness.
  8.  



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Fig. Fig. 15: Measuring valve guide wear

RESURFACING



Cylinder Head Flatness

See Figures 16 and 17

When the cylinder head is removed, check the flatness of the cylinder head gasket surfaces.

  1. Place a straightedge across the gasket surface of the cylinder head. Using feeler gauges, determine the clearance at the center of the straightedge.
  2.  
  3. If warpage exceeds 0.003 in. (0.07mm) in a 6 in. (152mm) span, or 0.006 in. (0.15mm) for gasoline trucks, and 0.008 in. (0.20mm) for the diesel trucks, over the total length, the cylinder head must be resurfaced.
  4.  



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Fig. Fig. 16: Checking the cylinder head for flatness across the head surface, at an angle



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Fig. Fig. 17: Checking the cylinder head for flatness straight across the head surface

  1. If necessary to refinish the cylinder head gasket surface, do not plane or grind off more than 0.010 in. (0.25mm) for gasoline vehicles, 0.002 in. 0.05mm, for the diesel trucks, from the original gasket surface.
  2.  

When milling the cylinder heads of V6 and V8 engines, the intake manifold mounting position is altered, and must be corrected by milling the manifold flange a proportionate amount. Consult an experienced machinist about this.

 
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