Isuzu KB P190. Manual — part 1175

7B1-94 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 7B1-95

Clutch Hub Spline Play

• Set a dial indicator to the clutch hub which requires

measuring.

226RS042

• Move the clutch hub as far as possible to the right

and left.

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 the 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 the 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.

7B1-96 MANUAL TRANSMISSION

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

the ring.

RTW57BSH000101

Legend

(1) Ring

(2) Outer Race and Roller Assembly

(3) Inner

Race

3. Install the bearing snap ring to the counter gear

shaft.

4. Apply engine oil to the needle bearing and the 2nd

gear thrust surfaces.

Install the needle bearing and the 2nd gear to the
mainshaft.

The 2nd gear dog teeth must be facing the
transmission rear side.

226RS046

5.

Assemble the 2nd inside ring, 2nd outside ring, and
the 2nd block ring.
• Apply engine oil to the synchronizer ring friction

surfaces.

226RS047

Legend

(1)

Block Ring

(2)

Outside Ring

(3)

Inside Ring

(4)

2nd Gear

(5)

Needle Bearing

MANUAL TRANSMISSION 7B1-97

6. Assemble the 1st-2nd synchronizer assembly by

performing the following steps:

1. Check that the inserts (3) fit snugly into the

clutch hub (5) insert grooves.

2. Check that the inserts springs (4) are fitted to

the inserts as shown in the illustration.

3. Check that the clutch hub (5) and the sleeve (6)

slide smoothly.

266RS049

7. Install the synchronizer assembly to the mainshaft.

The clutch hub face (with the heavy boss) must be
facing the 2nd gear side.

226RS048

8. Install the clutch hub snap ring by performing the

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

minimum clearance between the 1st-2nd clutch
hub and the snap ring.

226RS050

• There are three snap ring sizes available.
• The snap rings are color coded to indicate their

thickness as shown in the figure.

226RS021

Clutch Hub and Snap Ring Clearance

Standard: 0 - 0.1 mm (0 - 0.004 in)

Snap Ring Availability

Thickness Color

Coding

1.80 mm (0.071 in)

White

1.85 mm (0.073 in)

Yellow

1.90 mm (0.075 in)

Blue

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

ring to the mainshaft.

The snap ring must be fully inserted into the
mainshaft snap ring groove.