Isuzu KB P190. Manual - part 674

Engine Mechanical – V6 

Page 6A1–217 

 

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 – 395 

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 – 396 

Engine Mechanical – V6 

Page 6A1–218 

 

Piston Ring 

N O T E  

The ends of the expander must be facing 
toward the top of the piston. 

1 

Correctly orient the oil control ring expander (1) 
before installation.  

Figure 6A1 – 397 

2 

Using a piston ring expander, install the oil control 
ring assembly using the following procedure: 

3 

Install the expander ring (3). 

4 

Install the two oil scraper rings (4). Expand the rings 
only enough to clear the piston diameter. Over-
expanding the piston rings will distort or crack the 
rings. 

5 

Install the second (2) and top (1) piston rings as 
follows. 

Figure 6A1 – 398 

6 

Using the ring expander (1), install the second piston 
ring (2) onto the piston (3). Do not over-expand the 
ring. Repeat for the top ring. 

Figure 6A1 – 399 

Engine Mechanical – V6 

Page 6A1–219 

 

7 

Once the rings are installed, set the ring gaps for the 
oil control, second and top ring as follows. Use the 
piston location arrow for reference. 
• 

Lower oil control ring position (1). 

• 

Upper oil control ring position (2). 

• 

Top ring position (3). 

• 

Oil control ring expander position (4). 

• 

Second ring position (5). 

Figure 6A1 – 400 

Connecting Rod Bearing 

CAUTION

 

If the connecting rod bearings have been 
used in a running engine, they must be 
replaced with new connecting rod bearings 
for reassembly. 

1 

Clean the connecting rod (2) and the connecting rod 
cap bearing bore with a lint-free cloth. 

2 

Clean the oil from behind the connecting rod bearing 
halves. 

3 

Install a new upper connecting rod bearing (1) into 
position. Roll the bearing into position so the lock tang 
engages the alignment slot. The bearing must fit flush 
in the connecting rod. 

Figure 6A1 – 401 

4 

Install the lower connecting rod bearing (1) into 
position in the connecting rod cap (2). 

5 

Roll the bearing into position so the lock tang 
engages the alignment slot. The bearing must fit flush 
with the connecting rod cap. 

Figure 6A1 – 402 

Engine Mechanical – V6 

Page 6A1–220 

 

Reinstall 

Piston Connecting Rod and Connecting Rod Bearing Installation 

CAUTION

 

The piston is directional and must be 
installed in the engine block in the correct 
direction. The locating arrow on the top of 
each piston must be pointing toward the 
front of the engine. 

1 

Liberally lubricate the cylinder walls, piston rings and 
piston skirts with engine oil. 

2 

Select the correctly numbered piston/connecting rod 
assembly for the cylinder. A dot (1) showing correct 
piston orientation is located on the top of the piston. 

Figure 6A1 – 403 

3 

Install connecting rod guide pin set, Tool No.  
EN-46121 (1) into the connecting rod bolt holes. 

Figure 6A1 – 404 

4 

Compress the piston rings using a commercially 
available ring compressor. 

CAUTION

 

Extreme care must be used when installing 
the piston and connecting rod to ensure the 
rod does not scrape or nick the cylinder 
bore, oil jets, or crankshaft surfaces. 

5 

Using both hands from the top and bottom of the 
cylinder, slowly guide the piston (2) and connecting 
rod assembly into the cylinder. Do not allow the 
connecting rod to contact the cylinder wall. 

6 

When the ring compressor contacts the deck surface, 
gently tap the piston into the cylinder using the handle 
end of a dead-blow hammer. Guide the connecting 
rod onto the crankshaft bearing journal using 
connecting rod guide pin set, Tool No. EN-46121 (1) 
while gently tapping the piston into the cylinder with a 
soft-blow hammer. 

Figure 6A1 – 405