Isuzu KB P190. Manual - part 1161

7B1-38     MANUAL TRANSMISSION 

Inspection and Repair 

Make the necessary adjustments, repairs, and part
replacements if excessive wear or damage is
discovered during inspection. 

Block Ring and Dog Teeth Clearance 

 

• Use a thickness gauge to measure the clearance

between the block ring and the dog teeth. 

  

226RS035

If the measured value exceeds the specified limit,
the block ring must be replaced. 

 

Block Ring and Dog Teeth Clearance 

Standard Limit 

1.5 mm (0.059 in) 

0.8 mm (0.031 in) 

 

 

MANUAL TRANSMISSION     7B1-39 

1st-2nd Synchronizer (3-CONE) 

 

• Use a thickness gauge to measure the clearance

between the block ring and the dog teeth. 

  

226RS036

If the measured value exceeds the specified limit,
the 1st-2nd synchronizer assembly must be
replaced. 

 

Block Ring and Dog Teeth Clearance 

Standard Limit 

1.5 mm (0.059 in) 

0.8 mm (0.031 in) 

Block Ring and Insert Clearance 

 

•  Use a vernier caliper or thickness gauge to measure

the clearance between the block ring and the insert.

  

226RS037

If the measured value exceeds the specified limit,
the block ring and the insert must be replaced. 

 

 

 

Block and Insert Clearance 

 Standard  Limit 

3rd-4th 

3.46 - 3.76 mm 

(0.136 - 0.148 in) 

4.0 mm 

(0.157 in) 

1st-2nd

3.86 – 4.16 mm 

(0.152 - 0.164 in) 

4.9 mm 

(0.193 in) 

Rev.5th

3.59 - 3.91 mm 

(0.141 - 0.154 in) 

4.1 mm  

(0.161 in) 

Clutch Hub and Insert Clearance 

 

• Use a thickness gauge to measure the clearance 

between the clutch hub and the insert. 

  

226RS038

If the measured value exceeds the specified limit, 
the clutch hub and the insert must be replaced. 

 

Clutch Hub and Insert Clearance 

 Standard  Limit 

1st-2nd

3rd-4th 

0.01 – 0.21 mm 

(0.0004 - 0.0083 in) 

0.3 mm 

(0.012 in) 

Rev-5th

0.09 – 0.31 mm 

(0.0035 - 0.0122 in) 

0.4 mm 

(0.016 in) 

 

 

7B1-40     MANUAL TRANSMISSION 

Mainshaft Run-out 

 

•  Install the mainshaft to V-blocks. 

 

• Use a dial indicator to measure the mainshaft

central portion run-out. 

  

226RS039

If the measured mainshaft run-out exceeds the
specified limit, the mainshaft must be replaced. 

Mainshaft Run-out 

Limit: 0.05 mm (0.0020 in) 

 

Gear Inside Diameter 

 

• Use an inside dial indicator to measure the gear

inside diameter. 

  

226RS040

If the measured value is less than the specified limit,
the gear must be replaced. 

 

 

 

Gear Inside Diameter 

 Standard  Limit 

1st 

3rd 

45.000 - 45.013 mm 

(1.771 - 1.772 in) 

45.100 mm 

(1.776 in) 

2nd 

52.000 - 52.013 mm 

(2.047 - 2.048 in) 

52.100 mm 

(2.051 in) 

Rev. 

48.000 - 48.013 mm 

(1.889 - 1.890 in) 

48.100 mm 

(1.894 in) 

5th 

32.000 - 32.013 mm 

(1.259 - 1.260 in) 

32.100 mm 

(1.246 in) 

Reverse Idler Gear and Idler Gear Shaft 
Clearance 

 

• Use a micrometer to measure the idler gear shaft 

diameter. 

 

• Use an inside dial indicator to measure the idler 

gear inside diameter. 

  

226RS041

 

• Calculate the idler gear and idler gear shaft 

clearance. 

Idler gear inside diameter-idler gear shaft diameter = 
idle gear and idler gear shaft clearance. 

If the measured value exceeds the specified limit, 
the idle gear and/or the idler gear shaft must be 
replaced 

Idler Gear and Idler Gear Shaft Clearance 

Standard: 0.041 - 0.074 mm (0.0016 -0.0029 in) 

Limit: 0.150 mm (0.0059 in) 

 

MANUAL TRANSMISSION     7B1-41 

Clutch Hub Spline Play 

 

•  Set a dial indicator to the clutch hub which requires

measuring. 

  

226RS042

 

•  Move the clutch hub as far to the right and left as 

possible. 

Note the dial indicator reading. 

If the measured value exceeds the specified limit,
the clutch hub must be replaced. 

 

Clutch Hub Spline Play 

 Standard  Limit 

1st-2nd 

3rd-4th 

0 - 0.1 mm  

(0 - 0.004 in) 

0.2 mm  

(0.008 in) 

Rev. 5th 

0 - 0.2 mm  

(0 - 0.008 in) 

0.3 mm  

(0.012 in) 

Ball Bearing Play 

 

•  Use a dial indicator to measure the ball bearing play.

Ball Bearing Play 

Limit: 0.2 mm (0.008 in) 

 

 

  

226RS043

 

Reassembly 

  1. Install the center roller bearing to counter gear shaft.

•  Apply engine oil to the bearing inner and outer 

circumferences. 

•  Install the roller bearing in the proper direction. 

NOTE: Check that the outer race moves only in the 
direction of the arrow. 

  

226RS044

 2. Install the front roller bearing by performing the 

following steps. 
•  Use bearing installer 5-8840-2194-0 to install the 

front roller bearing inner race to the counter gear 
shaft. 

•  Install the outer race and roller assembly. 

The snap ring groove must be facing the 
transmission front side.