MITSUBISHI 4M50 Valve Adjusting Procedure, Valve Train Parts, Page 1 of 5
Inspection and Adjustment of Valve Clearances Service standards (Unit: mm {in.}) Location –
Maintenance item Mitsubishi 4M50 Valve Lash Clearance (when cold)
Standard value
Limit
Intake valve
0.4 MM {0.016 Inch}
–
Exhaust valve
0.5 MM {0.020 Inch}
–
Remedy Adjust
Mitsubishi 4M50 Tightening torque (Unit: N·m {lbf·ft, kgf·m}) Mark
Parts to be tightened
Tightening torque
Remarks
23.2 {17, 2.4}
–
30.4 to 35 {22 to 26, 3.1 to 3.6}
–
Bolt (cover installation) Bolt (rocker cover installation) Bolt (PCV pipe installation) Injection pipe (union nut installation) Bolt (injector installation) –
5.2 to 7.2 {3.8 to 5.3, 0.53 to 0.73}
–
Bolt (cylinder sensor installation)
8 {5.9, 0.82}
–
Lock nut (adjusting screw stopping)
20.6 {15, 2.1}
–
Special tools Mark
Tool name and shape
Part No.
Application
Cranking handle (design may vary)
MH063704
Turning the fan pulley
Fuel line wrench
HAZET 4550-1 SnapOn FRXM17
Tightening the fuel lines
Mitsubishi 4M50 Engine Parts contact: Email: EngineParts@HeavyEquipmentRestorationParts.com Phone: 269 673 1638
MITSUBISHI 4M50 Valve Adjusting Procedure, Valve Train Parts, Page 2 of 5
Rocker Cover Rubber
Injector Fuel Return Line
Injector Bolts 4M50 Injector Wire Harness
4M50 Injector Injector Line Injector Oring
Cylinder Sensor
Injector Sealing Washer Rocker Cover Bolts
Rocker Cover
Rocker Cover Gasket A Rocker Cover Gasket B
MITSUBISHI 4M50 Valve Adjusting Procedure, Valve Train Parts, Page 3 of 5 1 2 3 4 5 6
1 2 3 4 5
Oil filler cap Cover Rocker cover rubber Snap ring Fuel return hose Fuel line
Air inlet duct Gasket Intake throttle Gasket 4M50 Intake manifold
7 8 9 10 11 12
13 Rocker cover 14 4M50 Rocker cover gasket A 15 4M50 Rocker cover gasket B
Bolt (with hexagonal hole) 4M50 Injector 4M50 Injector O-ring 4M50 Injector Tip gasket PCV pipe Cylinder sensor
: Non-reusable parts PCV: Positive Crankcase Ventilation
Adjust the valves when the engine is cold. 1. Blank 2. Disconnect the EGR harness at the throttle body. 3. Remove the air inlet duct mounting bolts and remove the intake throttle. 4. Remove the oil cap. 5. Remove the cover. 6. Remove the rocker cover rubber. 7. Using compressed air, blow any debris from around the injectors. 8. Disconnect the fuel return lines. 9. Disconnect the wire harness from the injectors. 10. Remove the fuel return line mount bolts (one on the valve cover and one on the side of the engine). Carefully move the return line out of the way. 11. Remove the fuel lines. 12. Remove the injectors. 13. Disconnect the PCV pipe at the left of the engine and move it out of the way. 14. Remove the cylinder sensor. 15. Remove the rocker cover. 16. Rotate the engine until the number one cylinder is at TDC. The timing mark on the left camshaft will line up. Verify that the flywheel is also show-ing the “I, IV” mark. NOTE: Mark the flywheel for easy access later. Cylinder No.
1
2
3
4
Valve
IN
EX
IN
EX
IN
EX
IN
EX
No. 1 cylinder piston at TDC on compression stroke
O
O
O
–
–
O
–
–
No. 4 cylinder piston at TDC on compression stroke
–
–
–
O
O
–
O
O
Mitsubishi 4M50 Engine Parts contact: Email: EngineParts@HeavyEquipmentRestorationParts.com Phone: 269 673 1638
MITSUBISHI 4M50 Valve Adjusting Procedure, Valve Train Parts, Page 4 of 5 17. Adjust the valve clearances. • Loosen the lock nut. • Back off the adjuster screw and insert the feeler gauge under the rocker. • Tighten the adjuster screw until the feeler gauge drags slightly. • Hold the adjuster screw in position and tighten the lock nut. See tightening table. • Recheck the valve clearance with the thickness gauge, and readjust if the measurements are not within the specified value range. • Repeat for each valve. • Rotate the engine one turn to the #4 position, and adjust remaining valves.
18. Make sure that all 4M50 gaskets are securely in place and install the rocker cover. 19. Install the 4M50 injectors. 20. Connect the 4M50 fuel return lines. 21. Install the 4M50 fuel return line mount bolts. 22. Install the 4M50 fuel lines. 23. Position and connect the PCV pipe. 24. Install the rubber. 25. Install the cover. 26. Install the throttle body and air inlet duct. 27. Connect the EGR harness at the throttle body. 28. Start the engine and verify proper operation.
Mitsubishi 4M50 Engine Parts contact: Email: EngineParts@HeavyEquipmentRestorationParts.com Phone: 269 673 1638
MITSUBISHI 4M50 Valve Adjusting Procedure, Valve Train Parts, Page 5 of 5 Mitsubishi 4M50 Valve Train Parts Mitsubishi 4M50 Cylinder Head Parts Exhaust Rocker Arms Exhaust Rocker Arm Bushings Exhaust Rocker Arm Adjusting Screws Lock Nuts
Exhaust Rocker Shaft 4M50 Exhaust Manifold Side Exhaust Gaskets, Exhaust Studs, Bolts, Nuts,
Intake Rocker Arms 4M50 Intake Manifold Side Intake Gaskets, Intake Studs, Bolts, Nuts,
Intake Rocker Arm Bushings Intake Rocker Arm Adjusting Screws Locks Nuts
Intake Rocker Shaft Exhaust Rocker Shaft Valve Cotters
Upper Valve Spring Retainer Intake Rocker Shaft Intake Camshaft
Exhaust Camshaft
Outer Valve Spring
Valve Stem Seal
Inner Valve Spring
4M50 Exhaust Valve Guide Exhaust Valve Seat Exhaust Valve
Intake Valve
4M50 Intake Valve Guide Intake Valve Seat
Rocker Shaft Spring
Head Bolts Intake Valves
• Mitsubishi 4M50 Engine Parts contact: Email: EngineParts@HeavyEquipmentRestorationParts.com
Exhaust Valves
Phone: 269 673 1638