Isuzu KB P190. Manual - part 1159

7B1-30     MANUAL TRANSMISSION 

 6. Mesh the 1st-2nd and 3rd-4th synchronizers with

both the 1st and 3rd gears (double engagement). 

  

226RS015

This will prevent the mainshaft from turning. 

  7. Install the new mainshaft hub nut. 

Use the mainshaft nut wrench 5-8840-2156-0 to 
tighten the mainshaft nut to the specified torque. 

Torque: 137 N

⋅⋅⋅⋅m (14.0 kgf⋅⋅⋅⋅m/101 lb⋅⋅⋅⋅ft) 

226RW214

 

 

 

 

  8. Use a punch to stake the mainshaft nut. 

  

226RW153

  9. Install the needle bearing, 5th block ring, and 5th 

gear. 

 10.  Apply engine oil to the counter reverse gear and the 

reverse gear. 

Install the counter reverse gear to the counter shaft.

The reverse gear projection must be facing the 
intermediate plate. 

  

226RW151

 

 

 

MANUAL TRANSMISSION     7B1-31 

 11. Install the counter 5th gear to the counter shaft. 

  

226RS019

 

12. Install the ball bearing and bearing snap ring by 

performing the following steps: 
•  Select the snap ring which will provide the 

minimum clearance between the ball bearing
and the snap ring. 

  

226RS020

 

 

•  There are six snap ring sizes available. 

The snap rings are color‐coded to indicate 
their thickness. 

  

226RS021

Ball Bearing and Snap Ring Clearance 

Standard: 0 - 0.15 mm (0 - 0.0059 in) 

 

Snap Ring Availability 

Thickness Color 

Coding 

1.1 mm (0.043 in) 

White 

1.2 mm (0.047 in) 

Yellow 

1.3 mm (0.051 in) 

Blue 

1.4 mm (0.055 in) 

Pink 

1.5 mm (0.059 in) 

Green 

1.6 mm (0.063 in) 

Brown 

•  Use a pair of snap ring pliers to install the snap 

ring to the counter gear shaft. 

The snap ring must be fully inserted into the 
counter gear shaft snap ring groove. 

 13.  Assemble the reverse idler shaft, reverse idler gear, 

thrust washer, and idle shaft pin into the reverse 
idler gear assembly. 

The thrust washer should be assembled with the oil 
groove faces to gear side. 

 

 

7B1-32     MANUAL TRANSMISSION 

14. Select the reverse idler gear snap ring which will

provide the minimum clearance between the
intermediate plate and the snap ring. 

  

226RS022

•  There are three snap ring sizes available. 

The snap rings are color-coded to indicate their
thickness. 

Intermediate Plate and Snap Ring Clearance 

Standard: 0 - 0.15 mm (0 - 0.0059 in) 

 

Snap Ring Availability 

Thickness Color 

Coding 

1.2 mm (0.047 in) 

White 

1.3 mm (0.051 in) 

Yellow 

1.4 mm (0.055 in) 

Blue 

  

226RS021

 

 

•  Use a pair of snap ring pliers to install the snap 

ring to the reverse idler shaft. 

The snap ring must be fully inserted into the 
reverse idler shaft snap ring groove. 

 15. Install the thrust washer and lock ball by performing 

the following steps: 
•  Use a thickness gauge to measure the 

clearance between the 5th gear and the thrust 
washer. 

5th Gear and Thrust Washer Clearance 

Standard: 0.10 - 0.25 mm (0.004 - 0.010 in) 
•  Measure clearance "A" as shown in the figure. 

  

226RS023

•  Select an appropriate thrust washer from the 

chart. 

•  There are four thrust washer sizes available. 

 

Thrust Washer Availability 

Thickness 

mm (in) 

Color 

Coding

A mm (in) 

Clearance 

mm (in) 

7.9 (0.311)

White 

8.05 - 8.1 

(0.317-0.319) 

0.15 - 0.25 

(0.006-0.010)

8.0 (0.315)

Yellow

8.1 - 8.2 

(0.319-0.323) 

0.1 - 0.25 

(0.004-0.010)

8.1 (0.319)

Green

8.2 - 8.3 

(0.323-0.327) 

0.1 - 0.25 

(0.004-0.010)

8.2 (0.323)

Blue 

8.3 - 8.36 

(0.327-0.329) 

0.1 - 0.21 

(0.004-0.008)

•  The thrust washers are color-coded to indicate 

their thickness, as shown in the figure. 

 

 

 

 

MANUAL TRANSMISSION     7B1-33 

  

226RS024

•  Apply grease to the thrust washer and the lock

ball. 

•  Install the thrust washer and the lock ball. 

 16. Install the thrust plate and retainer. 

 17. Install the retainer snap ring, clip, speedometer drive

gear and bearing snap ring. 

 18.  Apply engine oil to the bearing inner and outer

circumference. 

Use the installer 5-8840-2159-0 to install the ball
bearing to the mainshaft. 

226L100002

 

 

 19. Install the bearing snap ring.