ISUZU Heavy Duty Machine Repair: ISUZU Engine Brake Piston and Connecting Rod Removal and Installation

This article is about how to disassemble and Installation ISUZU4JJ1 Euro 4 N Series engine piston and connecting rod

ISUZU Truck Workshop Service Repair Manual PDF

Removal5. Remove the gearcase assembly.

1. Remove the engine assembly from the vethicle.. Referto"Gearcase Assembly inthis Section.

6. Remove the crankcase and oil pan.

Refer to Engine Assembly"in this Section. Refer to-o pan and crankcase"in Section 1H,

2. Remove the cylinder head cover.

Engine Lubrication.

Refer to "Cylinder Head Cover"in this Section.

7. Remove the connecting rod cap.

3. Remove the camshaft assembly.

Refer to "Camshaft Assembly"in this Section. NOTE:

4. Remove the cylinder head.

Organize the removed bearings by cylinders using Refer to"Cylinder Head"in this Section. tags, etc.

8. Remove the piston and connecting rod.

Remove carbon from the top of the cylinder block using a scraper.

Pull out the piston and connecting rod out to the cylinder head side.

NOTE: When pushing out the connecting rod, be careful not to damage the oil jet and cylinder block.

9. Remove the connecting rod bearing.

NOTE:

When reusing the bearing, organize them according to the order of the cylinders so that other cylinder bearings do not get mistaken.

Disassembly

Remove the piston ring.

Remove the piston ring using the ring pliers.

NOTE: When reusing the piston rings, organize them according to the order of the cylinders so that other cylinder pistons and piston rings do not get mistaken.

2. Remove the snap ring.

NOTE: Do not reuse the snap ring.

3. Remove the piston pin.

NOTE: Organize the disassembled piston pins, pistons and connecting rods according to the cylinders.

4.Remove the connecting rods from the pistons.

5.Piston

Carefully clean carbon from the piston heads and piston ring grooves.

NOTE:

Do not use a wire brush to clean the pistons.

Visually inspect the pistons for cracks, seizure or other excessive wear. If there is an abnormality, replace the piston.

replace the piston.

Inspection

1. Measure the clearance between the piston and the inner diameter of the cylinder block.

Cylinder block inner diameter

Use the cylinder bore gauge to measure the inner diameter of the cylinder block in the thrust direction and the radial direction at the specified position.

Measuring position: from the top surface of the cylinder block.

(1)20mm(0.79 in)(2)80mm(3.15 in)(3)140mm(5.51in)

Find the cylinder block inner diameter according to the average value(excluding the maximum and minimum values) of the 6

locations actually measured.

Legend

1.20mm(0.79 in)2.80mm(3.15 in)

3.140mm(5.51 in)

Radial direction5. Thrust direction

Piston outer diameter

Use a micrometer to measure the outer diameter of the piston in the specified position.

. Measuring position:11 mm(0.433 in) from the lower end of the piston skirt

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NOTE:

If the clearance between the piston and the inner diameter of the cylinder block exceeds the standard value, replace the piston.

2. Replace the piston

The A,B, and Cmarks on the top surface of the piston indicate the grades.

Legend

1.Grade

2.Front mark

3.Inspect the piston ring.

Remove carbon from the joint.

Measure the joint clearance at where the cylinder inner diameter is smallest, using a thickness gauge, between measurement locations 1 and 2.

Replace the piston ring if the measured value exceeds the limit.

Measure the clearance between the piston ring groove and the piston ring.

remove all carbon in the piston ring groove.

· Insert the piston ring into the piston ring groove, and measure the clearance with the thickness gauge.

· If the clearance between the piston ring groove and the piston ring exceeds the standard value, replace the piston or piston ring.

*Measurement is impossible

LNW21BSH0095014. Inspect the piston pin.

Visually inspect the piston pin for cracks, scratches or other damages, and replace it as necessary.

Use a micrometer to measure the outer diameter of the piston pin. Replace the piston pin if the measured value exceeds the limit.

Inspect for a certain degree of resistance when the piston pin is lightly pushed in, when the piston is at room temperature.

Replace the piston or the piston pin if they feel loose at room temperature.

· Measure the inner diameter of the connecting rod small end bushing. If the clearance between the bushing inner diameter and pin outer diameter exceeds the limit, replace the bushing or the connecting rod assembly, and pin.

5. Measure the clearance between the piston and the .

piston pin.

Apply engine oil to the piston pin. Then, manually push it into the piston hole and rotate it. If the pin rotates smoothly without any looseness, the clearance is normal. If there is looseness, measure the clearance. Replace the piston and piston pin if the clearance exceeds the limit.

6. Measure the connecting rod alignment.

Use the connecting rod aligner to measure the twisting of the large end hole and small end hole, and the degree of parallelization. Make replacements if the measured value exceeds the limit.

LNW21BSH0104017. Measure the bearing olil clearance.

Use the following method to measure the oilclearance between the connecting rod bearing and crank pin.

-Remove the connecting rod caps. Set the removed caps in the order of the cylinder number.

-Clean the bearing and crankshaft pin.

-Inspect the bearing. Replace the bearings in sets if there is damage or excessive wear.

Place the plastigauge on the crankshaft pin.

Install the connecting rod cap, and tighten boltat the specified torque in the order as shown in the diagram.

Apply engine oil to the threaded portion of the tightening bolts and seat surface and tighten them at the specified torques.

Reassembly

1. Install the piston.

2. Install the connecting rod.

Assemble so that the piston head front mark(1)

and connecting rod cast mark (convex)(2) face the same direction.

Install the snap ring on one side.

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3. Apply an adequate amount of engine oil to the piston pin. Then, push it into the piston and connecting rod small end.

4. Install the snap ring.

NOTE:

Check that the snap ring is securely installed in the ring groove. Check that the connecting rod slides smoothly.

5. Install the piston ring using the ring pliers.

?Install the oil ring so that the coil expander joint is 180?in the opposite direction.

The compression ring is installed with the mark facing upward, and install in the order of No.2

and No.1 compression rings.

Installation

1. Install the connecting rod bearing.

?Install the bearing to the connecting rod, and apply engine oil to the bearing.

2. Install the piston and connecting rod assembly.

?Thoroughly apply engine oil to the piston ring, ring groove and piston side surface.

?Shift alternately as shown in the diagram for the piston ring joint to the No.1 ring for(1), the No.

2ring for(2), and the oil ring for(3).

Face the piston front mark(notch) towards thefront, and insert the piston into the cylinder block using the installer.

RTW56ASH023201

Legend

1. No.1 Compression ring2. No.2 Compression ring

3. Oil ring4. Expander NOTE:

When pushing the piston, firmly attach the setting tool to the cylinder block and push in. If the adherence is inadequate, the ring can be damaged when pushed.

When pushing the piston, be careful not to touch the oil jet against the connecting rod.

Be careful not to damage the inner surface of the block when inserting the piston.

3. Install the connecting rod cap.

?Install the bearing to the connecting rod cap and apply engine oil.

?Align the cap and the connecting rod number markings(1,2,3,4) and install the cap.

apply engine oil to the threaded portion of the tightening bolts and seat surface and tighten bolt at the specified torque in the order as shown in the diagram.