Isuzu KB P190. Manual - part 681

Engine Mechanical – V6 

Page 6A1–245 

 

1 

It is critical the drilling, counter boring and tapping of 
the hole to be repaired follows the same centreline (1) 
as the original hole. 

Figure 6A1 – 462 

2 

During the drilling and tapping of the hole being 
repaired, ensure the tooling is consistently machining 
perpendicular to the surface of the base material. 

Figure 6A1 – 463 

3 

If the threaded hole being repaired has a base 
surface perpendicular to the hole centreline, tapping 
guides are available to aid in tapping the hole. 

 

 

Tap 

Size 

Tap 

Guide 

Tap 

Size 

Tap 

Guide 

Tap 

Size 

Tap 

Guide

- J 

42385 

- J 

42385 

- J 

42385

6 x 1.0 

729 

10 x 

1.5 

731 14 

x 

1.5 

736 

8 x 

1.25 

730 12 

x 

1.5 

732 20 

x 

1.5 

737 

 

Figure 6A1 – 464 

Engine Mechanical – V6 

Page 6A1–246 

 

General Thread Repair 

N O T E  

The use of a cutting type fluid such as WD 40® or 
equivalent is recommended when performing the 
drilling, counter boring and tapping procedures 

1 

When installed to the correct depth, the flange (1) of 
the insert will be seated against the counter bore of 
the drilled/tapped hole and just below the surface (2) 
of the base material. 

 

 

Figure 6A1 – 465 

N O T E  

During the drilling process, repeatedly remove 
the drill and clean the swarf from the hole and 
the flutes of the drill. 

CAUTION

 

Do not drill any further than the original hole 
depth. 

2 

Drill out the threads of the damaged hole to the 
correct depth for the thread being repaired: 
• 

M6 inserts require a minimum drill depth of 15 
mm. 

• 

M8 inserts require a minimum drill depth of 20 
mm. 

• 

M10 inserts require a minimum drill depth of 
23.5 mm. 

 

Figure 6A1 – 466 

N O T E  

All swarf must be removed from the drilled hole 
prior to tapping. 

 

Safety glasses must be worn when using 
compressed air. 

3 

Using compressed air, clean out any swarf. 

 

Figure 6A1 – 467 

Engine Mechanical – V6 

Page 6A1–247 

 

N O T E  

A correctly counter bored hole will show a slight 
burnishing on the surface of the base material 
for 360 degrees around the drilled hole. 

4 

Counter bore the drilled hole to the full depth 
permitted by the tool (1). 

 

Figure 6A1 – 468 

N O T E  

All swarf must be removed from the drilled hole 
prior to tapping. 

 

 

Safety glasses must be worn when using 
compressed air. 

5 

Using compressed air, clean out any swarf. 

Figure 6A1 – 469 

N O T E  

•  During the tapping process, repeatedly 

remove the tap and clean the swarf from the 
hole and the flutes of the tap. 

•  Ensure the tap has created full threads at 

least to the depth equal to the insert length. 

6 

Using a suitable tapping wrench, tap the threads of 
the drilled hole by hand only. 
• 

M6 inserts require a minimum drill depth of 15 
mm. 

• 

M8 inserts require a minimum drill depth of 20 
mm. 

• 

M10 inserts require a minimum drill depth of 
23.5 mm. 

Figure 6A1 – 470 

Engine Mechanical – V6 

Page 6A1–248 

 

N O T E  

All swarf must be removed from the tapped hole 
prior to insert installation. 

 

Safety glasses must be worn when using 
compressed air. 

7 

Using compressed air, clean out any swarf. 

Figure 6A1 – 471 

8 

Spray a commercially available thread cleaner into 
the tapped hole. 

Figure 6A1 – 472 

N O T E  

All swarf must be removed from the tapped hole 
prior to insert installation. 

 

Safety glasses must be worn when using 
compressed air. 

9 

Using compressed air, clean out any swarf. 

 

 

Figure 6A1 – 473