How to Disassemble the Yanmar 3TNV series and 4TNV series Engine Cylinder Head: Disassembly, Inspection and Reassembly

 This article describes how to disassemble the Yanmar 3TNV series and 4TNV series engine Cylinder Head: Disassembly, Inspection and Reassembly

 For Yanmar Diesel Engine Agriculture Excavator Tractor Marine Generator Diagnostic tool

 

 09.2024 Yanmar SA-Direct 2.45 Offline Diagnostic Software

  Disassembly procedure:

Disassemble in the order of the numbers shown in the illustration.

1) Remove the alternator assy. (Point1)

2) Remove the fan, pulley and V belt.

    3) Remove the thermostat case. (Point2)

                        4) Remove the fuel filter and fuel oil piping. (Point3) 

5) Remove the oil level gage assy. 

6) Remove the oil filter. (Point4)

            7) Remove the fuel injection pipes. (Point5)

8) Remove the intake manifold assy.

9) Remove the exhaust manifold assy.

10) Remove the rocker arm cover Assy.

                                              11) Remove the rocker shaft assy, push rods and valve caps. (Point6)

                                12) Remove the cylinder head assy and head gasket. (Point7)

                                       13) Remove the fuel injection valves and fuel return pipe. (Point8)

                                             14) Remove the intake/exhaust valves, stem seals and valve springs. (Point9)

15) Remove the rocker arms from the rocker shaft.

2018 Yanmar Engine Diagnostic Service Tool Software

 

How to calibrate the cylinder of Yanmar 3TNV and 4TNV engines

This article describes how to calibrate the cylinders of Yanmar 3TNV and 4TNV engines

 

 

For Yanmar Diesel Engine Agriculture Excavator Tractor Marine Generator Diagnostic tool

1) Slight uneven worn, flawed, etc. shall be

corrected by honing only.    If the cylinder is

unevenly worn partially, flawed or otherwise

damaged and cannot be repaired simply by

honing, rebore the cylinder first and then hone. See 4.4.5.(1)(c) for the boring dimension.

2) Items to be prepared for honing

l Flex-Hone

(see No.8 of 4.1.2 in Chapter 4)

l Electric drill

l Honing fluid

(50:50 mixture of lube oil and diesel oil)

 

 09.2024 Yanmar SA-Direct 2.45 Offline Diagnostic Software

 

3) Apply the honing fluid to the Flex-Hone and turn   the electric drill at 300 to 1200 rpm.    Then insert the Flex-Hone into the cylinder bore while turning it, and move it up and down for about 30 sec. to   obtain a honing mark with a cross hatch angle of

30 to 40 .

[NOTICE]

1) Avoid faster revolution than 1200 rpm since it may cause breakdown.

2) Do not insert or extract the Flex-Hone in    stopped state because the cylinder will be 

                                                                              

2018 Yanmar Engine Diagnostic Service Tool Software