Isuzu KB P190. Manual - part 762

Engine Mechanical – V6 

Page 6A1–271 

 

Page 6A1–271 

Piston Ring Measurement 

1 

Measure the piston ring end gap using the following 
procedure: 

a 

Place the piston ring (1) in the area of the bore where 
the piston ring will travel, approximately 25 mm below 
the deck surface. Ensure the ring is square with the 
cylinder bore by positioning the ring with the piston 
head. 

b 

Measure the end gap of the piston ring with feeler 
gauges (2), refer to 

5  Specifications

. 

c 

If the clearance exceeds the provided specifications, 
the piston rings must be replaced. 

d 

Repeat the procedure for all piston rings. 

 

Figure 6A1 – 478 

2 

Measure the piston ring side clearance using the 
following procedure: 

a 

Roll the piston ring (1) entirely around the piston ring 
groove. If any binding is caused by the ring groove, 
dress the groove with a fine file. If any binding is 
caused by a distorted piston ring, replace the ring. 

b 

With the piston ring on the piston, use feeler 
gauges (2) to check clearance at multiple locations. 

c 

Compare the measurements with piston ring side 
clearance listed in the specifications, refer to  

5  Specifications

. 

d 

If the clearance is greater than specifications, replace 
the piston rings. 

 

Figure 6A1 – 479 

3 

There is a locating dimple (1) on the compression 
rings. Install the compression rings with the dimple 
facing up. 

4 

If the new ring does not reduce the clearance to the 
correct specification, install a new piston. 

5 

If the new piston does not meet clearance 
specifications, the cylinder block may need to be 
oversized to 0.25 mm. There is only one size of 
oversized pistons and rings available for service. 

 

Figure 6A1 – 480 

Engine Mechanical – V6 

Page 6A1–272 

 

Page 6A1–272 

Connecting Rod Cleaning Procedure 

1 

Clean the connecting rods in solvent. 

 

Safety glasses must be worn when using 
compressed air. 

2 

Dry the connecting rod using compressed air. 

3 

Remove the connecting rod cap and clean the threads. 

4 

Remove the connecting rod bearing and discard. Never reuse a connecting rod bearing that has been used in a 
running engine. 

Connecting Rod Visual Inspection Procedure 

1 

Inspect the piston pin bushing (4) for scoring or 
damage. 

2 

Inspect the connecting rod beam (1) for twisting or 
bending. 

3 

Inspect the rod cap (2) for any nicks or damage 
caused by possible interference. 

4 

Inspect for scratches or abrasion on the rod bearing 
seating surface. 

5 

If the connecting rod bores contain minor scratches or 
abrasions, clean the bores in a circular direction with 
a light emery paper. 

6 

Retain the original bolts (3) for preliminary assembly. 
They must be replaced for final assembly. 

 

Figure 6A1 – 481 

Connecting Rod Measurement Procedure 

Piston Pin End 

N O T E  

Measurements of all components should be 
taken with the components at normal room 
temperature. 

1 

Using an outside micrometer (1), take two 
measurements of the piston pin (2) in the area of the 
connecting rod contact. 

 

Figure 6A1 – 482 

Engine Mechanical – V6 

Page 6A1–273 

 

Page 6A1–273 

2 

Using an inside micrometer, measure the connecting 
rod piston pin bore (1). 

3 

Subtract the piston pin diameter from the piston pin 
bore. 

4 

Compare the clearance measurements listed in the 
specifications, refer to 

5  Specifications

. 

5 

If the clearance is excessive, replace the piston pin. If 
a new pin does not resolve the clearance problem, 
replace the connecting rod. 

 

Figure 6A1 – 483 

Crankshaft Bearing End 

N O T E  

Measurements of all components should be 
taken with the components at normal room 
temperature. 

1 

Using an inside micrometer, measure the connecting 
rod crankshaft bearing bore (1). 

2 

Compare the bore measurements listed in the 
specifications, refer to 

5  Specifications

. 

3 

Replace the connecting rod if the bore is out of 
specification. Do not recondition the connecting rod. 

 

Figure 6A1 – 484 

Engine Mechanical – V6 

Page 6A1–274 

 

Page 6A1–274 

Reassemble 

Piston and Piston Pin 

CAUTION

 

The arrow located on top of the piston must 
point toward the front of the engine. 

N O T E  

The connecting rod is non-directional and may 
be assembled/reassembled to the piston in 
either direction. 

1 

Lubricate the piston pin (1) bores in the piston (2) and 
the connecting rod with clean engine oil. 

2 

Assemble the piston and piston pin to the connecting 
rod. Correctly orient the piston when reusing a 
marked connecting rod. 

3 

Align the piston pin bore with the connecting rod pin 
bore. 

4 

Slide the piston pin into the piston and the connecting 
rod. 

 

Figure 6A1 – 485 

CAUTION

 

New piston pin retainers must be used. 
Never reuse the piston pin retainers. 

5 

Install new piston pin retainers (1). 

6 

Ensure the piston pin retainers are fully seated in their 
grooves. 

7 

Repeat steps 1 to 6 for the remaining pistons. 

 

Figure 6A1 – 486