4d94e Shop Manual

7/29/2019 4d94e Shop Manual

1/25

3.1

Fix it firmly because it may fall down and injure you or damage theparts during work.

CAUTION

CAUTION

When using the air, steam, and so on, foreign substances may bescattered and damage your eye, and so on. Be sure to wear a pro-

tective wear such as goggles.

(1)

(2)

(3)

INTRODUCTION ENGINE BODY

3-2

IntroductionPrepare the following prior to starting inspections and maintenance of the engine.

Fix the engine on a horizontal table.

Remove the cooling water hose, fuel oil pipe, wire harness, and so on connecting the engine to theforklift truck body to drain the cooling water, oil, and fuel.

Use detergent, air, steam, and so on to clean the engine by washing away earth, oil, dust, and so on

adhered to it. When this is done, be careful not to allow foreign substances into the engine.


2/25

Cylinder Head

Component Parts

ENGINE BODY CYLINDER HEAD

1st time T = 53.9 Nm (5.5 kgf-m)

2nd time T = 107.8 Nm (11 kgf-m)

At the time of disassembly, the packings, O-rings, and oil seals

must be all replaced by new parts; they are not reusable. Particu-larly, if a head gasket packing is reused, a blow-by of the combus-

tion gas may damage the explosion surfaces of the cylinder andcylinder head, and it is feared that you will not be able to reuse

them.

3-3

CAUTION

3.2

(1)


3/25

Disassembly ProcedureDisassemble in order of the numbers shown in the drawing.

Remove the alternator assembly. (Note 1)Remove the fan, pulley, and V-belt.Remove the water pump assembly.Remove the fuel filter and fuel oil pipe.Remove the oil gauge assembly.Remove the fuel injection pipe. (Note 2)Remove the intake manifold assembly,Remove the exhaust manifold assembly.Remove the cylinder head cover assembly.Remove the lever shaft assembly, push rod, and valve head protector. (Note 3)Remove the cylinder head assembly and head gasket. (Note 4)Remove the fuel injection valve and fuel return oil pipe. (Note 5)Remove the glow plug and lead wires.Remove the intake/exhaust valve and valve spring. (Note 6)Remove the valve lever from the lever shaft.

CYLINDER HEAD ENGINE BODY

Disassembly and Aassembly of Cylinder Head

(3)

3-4

(2)


4/25

Assembly ProcedureAssemble in the reverse order of disassembiy.

(Note 1) AlternatorDisassembly: Supporting the alternator,

loosen the mounting bolts.Assembly: Belt tension is 10 - 15 mm

(0.39 - 0.59 in) (7 - 9 mm (0.28 -0.35 in) for a new belt) at fingerpressure of 98 N(10 kgf) .

(Note 2) Fuel injection pipe

Disassembly and assembly:

Pump:

Cylinders:

(Note 3) Push rodAssembly:

(Note 4) Cylinder headDisassembly

Loosen the head bolts sequentially in twotimes.

Be careful not to scratch the combustion)surface.

AssemblyApply oil to the threads and seat surface of

the head bolts and set them uniformly.When tightening them, do so in two timesin reverse order of disassembly.

1st-time torque

2nd-time torque

Note combinations of the pumps A, B, C, and D marks with the cylin-der numbers.A-4, B-2, C-1, D-3

Marked on the delivery section of the main body

Numbered in order of 1, 2, 3, and 4 from the flywheel side

Be sure to apply oil to the contact with a valve clearance adjusting screw.

3-5

1)

2)

1)

2)

T=53.9Nm (5.5kgf-m)

Support the alternator firmly. Otherwise, you may have your fin-ger caught or damage the parts.

T=107.8Nm (11kgf-m)

(4)


CAUTION


5/25

Inspection and Measurement of Parts

Cylinder headInspection of the combustion surface andmeasurement of distortion.Distortion of the combustion surface

Clean the combustion surface, apply astraight edge to two diagonal directionsand four peripheral directions and use athickness gauge to measure deformation

of the combustion surface.

Inspection of the combustion surfaceWhen cracks are suspected, examine by a

color check.

Wear measurement of the intake/exhaustvalve seat

Clean the valve seat and measure valvesinking and seat width. Depending on thecircumstances, paint the valve in blue and

check for a contact.

Measurement of valve sinking

(Note 5) Fuel injection valve

Disassembly: Note that the protector at the nose will remain in the cylinder headAssembly: Unless there is a gas leak, replace only the copper washer between the nozzle and

protector by a new one and assemble.

(Note 6) Intake/exhaust valveDisassembly: When there is a cotters burr at the shaft of the intake/exhaust valve, eliminate it with

an oilstone, and so on, and then, remove the valve from the cylinder head

Assembly:


Apply oil and assemble it, paying attention not to damage the stem seal.

After assembling the intake/exhaust valve, valve spring, holder, and cotter, fit in thespring by lightly hitting the head of the valve stem.

1)

2)

1)

a)

b)

2)

a)

3-6

(5)

(i)


6/25

Measurement of seat width

Intake/exhaust valve and valve guideWhen the intake/exhaust valve shaft isbent or greatly worn, replace it together

with the valve guide.Measurement of the outer diameter ofthe valve shaft and inner diameter of

the valve guide

Valve springReplace it if it has any abnormality suchas damage, corrosion.

Measurement of free length, inclina-tion, and spring tension

Locker arm, shaft, spring, push rod, valvehead protector, and valve clearance adjust-ing screw

Replace them if they have any abnor-mality such as damage, corrosion. Payadditional attention to the contact areabetween the locker arm and valve headprotector, corrosion and damage of thespring, bent of the push rod, and con-tact of both ends.

3-7

b)

(ii)

(iii)

(iv)

1)

2)

1)

2)

1)



7/25

Measurement of the inner diameter of thelocker shaft hole and outer diameter of theshaft

Correction of Valve Seat

When correcting the valve seat, check the clearance between the valve and valve guidefirst. If it is larger than the specified limit, replace the valve or valve guide to normalize theclearance, and then, correct the valve seat. After correcting the valve seat, wash the valve

and cylinder head fully with light oil, and so on to completely eliminate grinding powder,compound, and so on.

When the seat is slightly rough: Perform [A] and [B] below.When the seat is considerably rough, but the seat width is normal, correct with a seat grinder orseat cutter, and then, perform [A] and [B] below.

When the seat is considerably rough and the seat width is too large, grind or cut the seat surfacewith a 40 seat grinder or seat cutter, finish the seat width to the reference dimension with a 150

seat grinder, perform seat correction described in (ii) above, and then, perform [A] and [B] below.

[A]: Knead the valve compound and engine oil together, and fit the valve to the seat.

[B]: Fit with the engine oil alone.

(i)

(ii)

(iii)

3-8

IMPORTANT:

(6)

(2)



8/25

Replacement of Valve GuideUsing a drawout tool, draw out the valve

guide from the cylinder head.Put liquid nitrogen or ether/alcohot plus dryice in a container to cool a replacementvalve guide, and drive in with a valve guide

inserting tool.Finish to a reference inner diameter with areamer.Check a projection amount from the cylin-

der head.

Replacement of Valve Stem Seal

Whenever the intake/exhaust valve is disassembled, be sure to replace it by a new one.To reassemble it, apply grease to a stem seal, push it in with an inserting tool to install it. Only theexhaust side is painted in yellow. Be careful not to mistake the intake side for the exhaust side.

Do not touch a cooled valve guide with a naked hand. The skinmay be damaged.


Projection amount: 15 mm (0.59 in)

(7)

(8)

(i)

(ii)

(iii)

(iv)

(i)(ii)

CAUTION

3-9


9/25

Gear Train and Cam Shaft

Component Parts

GEAR TRAIN AND CAM SHAFT ENGINE BODY

Crank pulley

Fuel injection pump gearFlywheelNon-reusable partpply liquid packing

Apply grease

T = 117.6 Nm(12 kgf-m) T = 63.7 Nm(6.5 kgf-m) T = 196 Nm(20 kgf-m)

3-10

3.3

(1)


10/25

Disassembly ProcedureDisassemble in order of the numbers shown in the drawing.

Take the cylinder head disassembly procedural steps through .Remove the fuel injection pump drive gear cover.Remove the fuel injection pump. (Note 1)Remove the crank shaft pulley. (Note 2)Remove the gear case cover. (Note 3)Remove the idle gear assembly. (Note 4)Remove the PTO drive gear. (Note 5)Remove the PTO injection pipe.Remove the starting motor.Remove the flywheel. (Note 6)

Remove the cam shaft assembly. (Note 7)Remove the gear case. (Note 8)Remove the oil seal from the gear case cover. (Note 9)

Assembly ProcedureAssemble in the reverse order of disassembly.

Disassembly and Assembly of Gear Train and Cam Shaft

ENGINE BODY GEAR TRAIN AND CAM SHAFT

(2)

(3)

(4)

11

3-11


11/25

(Note 1) Fuel injection pumpDisassembly:

Remove fuel injection pump drive gearmounting nuts. Remove the gear by a gearpuller, using an M8 forcing screw. Loosenand remove fuel injection pump mounting

nuts. Remember to remove the rear stay.Assembly:

Make sure that an O-ring is set, and ad-just the fuel injection pump to a timing

mark.

Adjust the top mark to 6 (ATDC) pastthe top.Make sure that a plunger lift is 1 mm

(0.039 in).If it is not 1 mm (0.039 in), adjust apump body setting angle.

Set the fuel injection pump drive gear.Tightening torque T =

63.7 Nm(6.5 kgf-m)


(Note 2) Crank pulleyDisassembly:

Remove the crank pulley after removing pulley mounting bolts.Assembly:

Apply engine oil and assemble the crank pulley, paying attention not to damage the oil seal.Tightening torque T = 117.6 Nm(12 kgf-m)

(Note 3) Gear case coverDisassembly:

Remember to remove two middle reinforcing bolts.

Assembly:Measure a backlash for each gear.Apply liquid packing and set two knock pins together.

1)

2)

3)

4)

5)

1)2)

3-12


12/25

(Note 4) Idle gearAssembly:

Assemble the crank gear A, fuel injec-tion pump B, and cam gear C to the idlegears A, B, and C respectively at thesame time.Install the idle gear shaft with its oil holefacing upward.

(Note 5) PTO drive gearAssembly:

Set the inner spline side to the flywheel

side.

(Note 6) FlywheelDisassembly/Assembly:

Set a bolt in an M8 threaded hole in theend face of the wheel and use it as a han-dle. Be careful not to damage the ring gear.

(Note 7) Cam shaftDisassembly

Measure a side gap.

When the side gap is excessive, replace a thrust bearing. As the gear is shrink-fit, heat it to180 to 200C to remove it.

Put up the engine with the mounting flange facing down. Remove a cam shaft thrust bearingmounting bolt through a cam gear hole. Paying attention not to damage the bearing bush,remove the cam shaft. Turn the cam shaft a couple of times before removing it, so that thetappet will not be caught by the cam.

Assembly:After assembling the cam shaft, put back the engine horizontally and fix it onto the table.

When putting up the engine vertically or putting it back horizon-tally, it may fall down and injure you. Work carefully so that it willnot lose stability.

1)

2)

3)

CAUTION

1)

2)


3-13


13/25

(Note 8) Gear case

Disassembly:Remember to remove oil pan mounting bolts from below.

Assembly:Apply a liquid packing (No. 977770-01212) and set two knock pins together.

(Note 9) Oil sealAssembly:

When assembling, apply lithium grease.


Cam shaftCheck for a contact of the tappet with thecam surface, seizure of the bearing, wear,damage on the gear, and so on.

Measurement of the shaft bent

Measurement of Cam Height

Cam shaft outer diameter and bearing in-ner diameter

(i)

1)

2)

3)

3-14



14/25

Idle gearMeasurement of the idle gear shaft outer diameter and bushing inner diameter

PTO drive gear

Check both bearings for backlash and hitch, and gear shaft for any abnormality.

Replacement of Oil Seal

Remove the used oil seal.Insert a new one, using an oil seal inserting tool.Apply lithium grease.


(ii)

(iii)

1)

2)3)

(6)

3-15


15/25

Cylinder Block

Component Parts

Rod bolt T = 53.9 Nm(5.5 kgf-m) Metal cap T = 112.7 Nm(11.5 kgf-m) Non-reusable PartApply liquid packingApply grease

CYLINDER BLOCK ENGINE BODY

3.4

(1)

3-16


16/25

Disassembly and Assembly of Cylinder Block

ENGINE BODY CYLINDER BLOCK

(4)

3-17

12 .

11

(2)

(3) Disassembly ProcedureDisassemble in order of the numbers shown in the drawing.

Take the cylinder head disassembly procedural steps through .

Take the gear train disassembly procedural steps through .

Remove the oil pan. (Note 1)

Remove the lubricant suction pipe.Remove the piston W/rod. (Note 2)

Remove the flywheel housing. (Note 3)

Remove the metal cap. (Note 4)

Remove the crank shaft. (Note 5)

Remove the tappet.

Remove the piston pin and ring. (Note 6)

Remove the oil filter assembly. (Note 7)

Remove the oil seal from the flywheel housing. (Note 8)

Assembly ProcedureAssemble in the reverse order of disassembly.


17/25

(Note 1) Oil panDisassembly:

The liquid packing has been applied to its mounting surface to the block. Be careful not to causea damage or distortion on the adhering surface.

Assembly:Apply the liquid packing (code No. YM977770-01212) and assernble.

(Note 2) Piston W/rod

Disassembly:Measure the side gap of the rod.

Eliminate the carbon deposit accumulated on the cylinder carefully not to damage the inte-rior of the cylinder.Set the piston to BDC and remove the rod cap. Next, set the piston to TDC and push out therod larger end, using the wooden handle of a hammer. Care should be taken so that the rodlarger end will not be caught by the cylinder block.Set the rod cap and metal and assemble them.

Assembly:Apply oil elaborately to the slideways of the piston, rod, and ring.Incorporate into the block, using a piston inserting tool, and install the metal cap.Tightening torque T = 53.9 Nm (5.5 kgf-m)

(Note 3) Flywheel housingDisassembly:Paying attention not to damage, put the engine on the stable table with its explosion surfacefacing down, and remove the flywheel housing.

Assembly:Apply the liquid packing (code No. YM977770-01212) and set two knock pins together. After as-sembling, put up the engine with the flywheel housing facing down.

Standard mm (in) 0.10-0.20 (0.004-0.008)

CAUTION

When putting up the engine, it may fall down and injure you. Payattention to its stability.

3-18

1)

2)

3)

4)

1)2)



18/25

The crank shaft is heavy. When installing it, be careful not to dam-age the metal or injure your fingers.

3-19

CAUTION

Standard 0.11-0.21 mm(0.004-0.008 in)


1)

2)

3)

1)

2)3)

1)2)

(Note 4) Journal metal capDisassembly

Prior to removing the journal metal cap,measure the side gap of the crank shaft.

When the side gap is beyond the above-mentionedlimits, apply a thrust metal oversize.

Remove the metal cap, metal cap-side metal, and thrust metal. Put the thrust metal in such amanner that you can tell its position and direction.

AssemblyWhen assembling the thrust metal, its slotted side shoulld be outside to the cap.

Note that the upper metal (block side) has an oil hole and the lower metal (cap side) does not.Install the metal cap with its wheel, arrow mark facing the flywheel.Metal cap bolt tightening torque T = 112.7 Nm(11.5kgf-m)

(Note 5) Crank shaft

DisassemblyRemove the crank shaft.Remove the upper metal (block side) and assemble it to the metal cap.


19/25

(Note 6) Piston pin and ringDisassembly:

Remove the rings with a piston ring tool.Remove a circlip and push out the piston pin to remove it.

Assembly:Install the rings to the piston with their makers mark facing up. Shift ring splits by about 120

from each other.When assembling the piston pin to the rod and piston, the marking on the rod larger end andthe size marking on the crest of the piston should be on the opposite sides, respectively.Assemble to the block in such a manner that the marking at the rod larger end will face the

fuel injection pump. (The embossed marking on the rod body faces the flywheel)

(Note 7) Oil filterAssembly:

Close fully with hand, and then, tighten additionally by 3/4 turn with a filter wrench.

(Note 8) Oil seal:

Assembly:Apply lithium grease at the time of assembly.


Cylinder blockEliminate dirt, rust, adhesive agent, and so on. The oil hole should be cleaned thoroughly sothat it will not be blocked. When any cracks are suspected, make a color check to judge.


1)2)

1)

2)

3)

1)(i)

3-20

(5)


20/25

Use a cylinder gauge to measure the inner

diameter of each cylinder. Measure at thecrest, position 20 mm (0.29 in) from thelower end, and three central dimensions,

a, b, and c.Difference between the maxi-mum and minimum dimen-sions of a, b, and c

Difference in the respective di-mensions, a, b, and c, in thedirections, A and B.

When the dimension exceeds the above-mentioned limits or the cylinder is dam-

aged, repair it by boring or honing, and usean oversize piston as required.

Measurement of the cylinder inner diameter and distortion amount2)

3)

Roundness:

Cylindricity:

[Note] Measure the dimensions at a, b,

and c in both A- and B-directions.


3-21


21/25

Crank shaft

The crank gear has been shrink-fit. When itis necessary to remove it, heat it to 180 to200 C.

Check for cracks by a color check, orwith a magnetic defectoscope depend-

ing on the case.

Measurement of bent

1/2 of reading of the dial gauge

Measurement of the journal

When the oil clearance exceeds its limits,apply an undersize metal.


1)

2)

3)

Limit: 02 mm (0.0008 in) or less

(iii)

3-22


22/25

Measurement of the crank pin

Thrust metal

PistonEliminate the deposit on the expositionsurface, outer circumference, and ring

slots, not damaging the piston. If thering slots or snap ring slots have burr,deburr them. If cracks are suspected,make a color check to examine.

4)


(iii)

(iv)

1)

When the oil clearance exceeds the limits, usean undersize metal.

When thickness of the journal metal and crank pin metal is nor-mal and the oil clearance is excessive, or when local eccentricwear is recognized, regrind the crank shaft and use an oversizemetal.When the back of the metal is rusty or coarse, apply blue coloror minium, assemble with a specified torque and check for a

contact. It is normal if there is a contact of 3/4 or more. If thereis not a sufficient contact, a metal interference is not enough.Replace the metal.

1)

2)

IMPORTANT

When the side cap exceeds the limits, use an oversize metal.

3-23


23/25

Measurement of the piston large diameter

Measure at a position about 20 mm (0.8 in) fromthe lower end in the right-angled direction ofthe piston pin.

When the clearance from the cylinder exceedsthe limit, use an oversize piston.

Measurement of the piston pin hole

Piston rings


3-24

2)

3)

(v)


24/25

Except the top ring, when measuring thering groove width, measure the ring widthand put the ring in its groove. Use a thick-

ness gauge to measure the clearance be-tween the groove and ring. Add the meas-ured value to the ring width and assumethe sum to be the groove width.

To measure the clearance of the slit, pushthe ring into the cylinder by the head of thepiston and measure it with the thickness

gauge. Push it in as far as about 20 mm

(0.8 in) from the lower end of the cylinder.

Connecting rod

Care should be taken when the pistonbushing, crank pin metal, or both rodlarger and smaller ends have an ex-

treme local contact.

Measurement of the piston pin

When the oil clearance exceeds its limit

and you need to replace the bushing,use a replacement part, No. 129900-23910.

TappetPay attention to a contact with the camand push rod. If it has burr, eliminateit.

Measurement of the outer diameter


1)

2)

1)

2)

3-25

(vii)

(vi)


25/25

Honing

When satisfactory repair cannot be done only by honing, judging from the conditions of localeccentric wear, damage, and so on, perform boring first.

Prepare a flexible hone (code No. 129400-92430), electric drill, and honing liquid (mixed liquid ofthe engine oil and light oil).

Apply the honing liquid to the flexible hone. Running the electric drill at 300 to 1,200 rpm, insert

it into the cylinder bore and move up and down the flexible hone to hone the cylinder bore at 30to 40.

Do not run the drill at a higher rpm because it will lead to a breakage.Do not put in/out the flexible hone in its stopping state.The cylinder will be damaged.Each grinding allowance should be about 1/1,000 mm(1/25,000 in).

Replacement of Cam Shaft Bushing and Connecting Rod Bushing

Replace them by using their respective special purpose tools.

Replacement of Oil SealDraw out the used oil seal.Use an oil seal inserting tool to set a new oil seal.

Apply lithium grease.


(6)1)

2)

3)

1)2)

3)

IMPORTANT 1)2)

3)

(7)

(8)

Documents

4d94e Shop Manual