Page 4658 of 6020
7B1-52 MANUAL TRANSMISSION
2) NOISY OPERATION
Checkpoint Trouble Cause Countermeasure
Replenish or replace the gear
oilInsufficient or improper engine
oil
NG
Replace the gear(s)
Replace the gear(s)
Replace the bearing(s)
Gears (Gear whining)Lack of backlash between
meshing gears
Free running gears seizing on
the thrust face or the inner
face
Bearings (Hissing, thumping
or bumping)W orn or broken bearing(s)
Gears (Squealing at high
speeds)
Replace the gear(s)Gears (Growling, humming, or
grinding)W orn, chipped, or cracked
gear(s)
NG
NG
NG
NG
OK
OK
OK
OK
Gear oil (Metallic rattling)
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Page 4659 of 6020
MANUAL TRANSMISSION 7B1-53
2. HARD SHIFTING
Checkpoint Trouble Cause Countermeasure
Change lever play
Clutch pedal free play
Repair or replace the
applicable parts and regrease
Readjust the clutch pedal free
play
W orn change lever sliding
portions
Improper clutch pedal free
play
Change lever operationRepair or regrease the change
lever assembly
Replenish or replace the
engine oil
Hard operating change lever
caused insufficient grease
Insufficient or improper gear
oil
OK
OK NG
NG
NG
NG
OK
OKGear oil
Continued on the next page
Shift rod and quadrant box
sliding faces, and other partsReplace the shidt rod and/or
the quadrant boxW orn shift rod and/or sliding
faces
Repair or replace the sleeveSleeve movement failure
NG
NG
OKShift block sleeve movement
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Page 4677 of 6020
MANUAL TRANSMISSION 7B1-71
Transmission Case
Major Component
RTW 77BLF003701
Legend
(1) Gear Control Box Assembly and Gasket (7) Counter Front Bearing Snap Ring
(2) Rear Case Assembly (8) Front Cover (with Oil Seal)
(3) Intermediate Plate with Gear Assembly (9) Top Gear Bearing Snap Ring
(4) Transmission Case (10) Release Bearing: C24SE
(5) Release Bearing (with Spring): Diesel engine (11) Shift Fork: C24SE
(6) Shift Fork and Cover: Diesel engine
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Page 4678 of 6020

7B1-72 MANUAL TRANSMISSION
Disassembly
1. Clean the exterior of the unit with solvent.
2. Remove the drain plug from the transmission case and drain the lubricant.
3. Remove the clutch release bearing with spring from the transmission case.
4. Remove the shift fork, and boot.
5. Remove the front cover and gasket from the transmission case.
6. Remove the snap ring fixing counter front bearing.
7. Use a pair of snap ring pliers to remove the snap ring fixing top gear bearing.
226RS001
8. Remove the gear control box assembly.
9. Remove the rear case assembly from the transmission case and intermediate plate.
10. Remove the intermediate plate with gear assembl
y
from the transmission case.
Rear Oil Seal Replacement
220R300025
Legend
(1) Installer 5-8840-2797-0
(2) Grip 5-8840-0007-0
1. Remove the oil seal from the rear case and discard the used oil seal.
2. Apply engine oil to the new oil seal outer surfaces.
3.
Apply recommended grease (BESCO L2) or
equivalent to the oil seal lip.
4. Use the oil seal installer 5-8840-2797-0 and grip 5- 8840-0007-0 to install the oil seal to the rear case.
Reassembly
1. Apply recommended liquid gasket (Three Bond TB1215) or its equivalent to the transmission case,
intermediate plate and rear case fitting surfaces.
2. Install the intermediate plate with gear assembly to the transmission case.
Pull out the top gear shaft until the ball bearing snap
ring groove protrudes from the transmission case
front cover fitting face.
Avoid subjecting the mainshaft to sudden shock or
stress.
3. Install the rear case with oil seal on the intermediate plate, with gear, by performing the following steps.
• Cover the shaft splines with adhesive tape.
This will prevent damage to the oil seal lip.
• Tighten the transmission rear case bolts and
nuts to the specified torque.
Torque: 37 N ⋅
⋅⋅
⋅
m (3.8 kgf ⋅
⋅⋅
⋅
m/27 lb ⋅
⋅⋅
⋅
ft)
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Page 4679 of 6020

MANUAL TRANSMISSION 7B1-73
mm (in)
RTW 77BSH008601
Notes When Tightening the Bolt:
• After cleaning the bolt hole, air dry it thoroughly.
•
After cleaning the screw face of a removed or new
bolt, dry it thoroughly. Apply recommended liquid
gasket (LOCTITE 242) or its equivalent before
tightening.
4. Install a new gasket and gear control box assembly. Install the harness clips and brackets and then
tighten the four new gear control box bolts to the
specified torque.
Torque: 20 N ⋅
⋅⋅
⋅
m (2.0 kgf ⋅
⋅⋅
⋅
m/14 lb ⋅
⋅⋅
⋅
ft)
261R300004
5. Install the top gear bearing snap ring and counte
r
front bearing snap ring.
• Use a pair of snap ring pliers to install the snap
rings to the mainshaft and countershaft.
• The snap rings must be fully inserted into the
bearing snap ring groove.
6. Front cover with oil seal. Front Cover Oil Seal Replacement • Remove the oil seal from the front cover.
• Apply engine oil to the outer circumference o
f
new oil seal.
• Apply recommended grease to the oil seal lip.
• Use the oil seal installer 5-8840-0026-0 to install
the oil seal to the front cover.
220R300002
7. Install a new gasket and front cover to the transmission case.
NOTE: Take care not to damage the oil seal.
Notes When Tightening the Bolt:
• After cleaning the bolt hole, air dry it thoroughly.
•
After cleaning the screw face of a removed or new
bolt, dry it thoroughly.
Apply recommended liquid
gasket (LOCTITE 242) or its equivalent before
tightening.
Tighten the six front cover bolts to the specified
torque.
Torque: 25 N ⋅
⋅⋅
⋅
m (2.6 kgf ⋅
⋅⋅
⋅
m/19 lb ⋅
⋅⋅
⋅
ft)
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Page 4690 of 6020
7B1-84 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)
226RW 214
8. Use a punch to stake the mainshaft nut.
226RW 153
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.
226RW 151
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Page 4693 of 6020
MANUAL TRANSMISSION 7B1-87
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. Apply engine oil to the bearing inner and oute
r
circumference.
Use the installer 5-8840-2159-0 to install the ball
bearing to the mainshaft.
226L100002
18.
Apply engine oil to the oil seal collar inner
circumference.
Install the oil seal collar to the mainshaft by using
the installer 5-8840-2159-0.
19. Install the oil seal collar snap ring.
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Page 4701 of 6020

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 counte
r
gear shaft.
• Install the outer race and roller assembly.
The snap ring groove must be facing the
transmission front side.
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007