ISUZU KB P190 2007 Workshop Repair Manual

7A4–56 UNIT REPAIR (AW30–40LE)
Apply compressed air into the oil passage as
shown, and be sure that the OD brake piston moves
smoothly.
252RY00043

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ISUZU KB P190 2007

UNIT REPAIR (AW30–40LE) 7A4–57
Direct Clutch Assembly (C-2)
Disassembled View
RTW77AMF000401
EndOFCallout
Legend(1) Direct clutch drum
(2) O-ring
(3) Direct clutch piston
(4) Piston return spring (5) Snap ring
(6) Snap ring
(7) Flange
(8) Plate and disc Five plates and five discs

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ISUZU KB P190 2007

7A4–58 UNIT REPAIR (AW30–40LE)
Disassembly
Remove direct clutch drum assembly from forward
clutch assembly.
248RY00028
1. Check piston stroke of direct clutch (C –2).
Place the direct clutch assembly onto the OD
support assembly.
248RY00029
Using a dial indicator, measure the direct clutch
piston stroke by applying and releasing compressed
air (390 – 780 kPa or 57 – 114 psi) as shown.
Pack clearance: 0.5 – 0.8 mm (0.020 – 0.031 in)
RUW37ASH004901
2. Remove the clutch drum thrust washer (Plastic)
from the rear end of direct clutch.
3. Remove the snap ring from the direct clutch drum.
4. Remove the flange, plates and discs.
5. Place special tool on the spring retainer and compress the return spring.
Using snap ring pliers, remove the snap ring.
Spring compressor : 5-8840-0254-0
248RY00002
6. Remove the piston return spring.

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ISUZU KB P190 2007

UNIT REPAIR (AW30–40LE) 7A4–59
7. Place the direct clutch drum onto the OD support.Holding the direct clutch piston by hand, apply
compressed air to the OD support to remove the
direct clutch piston.
Remove the direct clutch piston from direct clutch
drum.
248RY00030
8. Remove two O-rings from piston.
Inspection and Repair
1. Check piston return spring. Using calipers, measure the free length of the return
spring.
Standard length: 21.3 mm (0.839 in)
247RY00034
2. Check discs. Using micrometer, measure the thickness of the
discs.
Minimum thickness: 2.04 mm (0.0803 in) If the thickness is less than the minimum, replace
the disc.
252RY00027
3. Check direct clutch piston. Check that check ball is free by shaking the piston.
Check that the valve does not leak by applying
low-pressure compressed air.
248RY00031

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ISUZU KB P190 2007

7A4–60 UNIT REPAIR (AW30–40LE)
4. Check direct clutch drum bushing.Using a dial indicator, measure the inside diameter
of the clutch drum bushing.
Maximum inside diameter: 53.99 mm (2.1256 in) If the inside diamater is greater than the maximum,
replace the clutch drum.
248RY00032
Reassembly
1. Coat new O-rings with ATF and install them on the direct clutch piston.
2. Install direct clutch piston to direct clutch drum. Being careful not to damage the O-rings, press in
the direct clutch piston into the clutch drum, using
both hands.
248RY00033
3. Install piston return spring.
248RY00034
4. Compress piston return spring and install snap ring in groove.
 Place special tool on the spring retainer, and
compress the return spring.
 Install the snap ring with snap ring pliers.
 Be sure the end gap of the snap ring is not
aligned with the spring retainer claw.
Spring compressor: 5-8840-0254-0
248RY00002

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ISUZU KB P190 2007

UNIT REPAIR (AW30–40LE) 7A4–61
5. Install four plates and four discs.Install in order : P –D –P –D –P –D –P –D
P : Plate, D : Disc
248RY00062
6. Install the flange, with the flat side facing downward.
248RY00035
7. Install the snap ring with a screwdriver. Be sure the end gap of the snap ring is not aligned
with the cutout portion of the direct clutch drum.
248RY00036
8. Check piston stroke of direct clutch (C –2).
Place the direct clutch assembly onto the OD
support assembly.
248RY00029Using a dial indicator, measure the direct clutch
piston stroke by applying and releasing compressed
air (390 – 780 kPa or 57 – 114 psi) as shown.
Pack clearance: 0.5 – 0.8 mm (0.020 – 0.031 in)
If the piston stroke is not within specification,
replace the discs and recheck the piston stroke.
If the piston stroke is nonstandard, select another
flange.

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ISUZU KB P190 2007

7A4–62 UNIT REPAIR (AW30–40LE)
Flange sizes
RUW37ASH004901
9. Coat the clutch drum thrust washer (plastic) withpetroleum jelly and install it onto the direct clutch.
NOTE: Make sure that the lugs fit into the cutout
portions on the direct clutch.
248RY00037
Align the flukes of discs in the direct clutch.
Install the direct clutch assembly onto the forward
clutch assembly.
Check that the distance from the direct clutch end to
the forward clutch end is 71.2 mm (2.803 in).
248RY00038
Flange thickness Flange thickness
3.3 mm (0.130 in) 3.8 mm (0.150 in)
3.4 mm (0.134 in) —
3.5 mm (0.138 in) 4.0 mm (0.157 in)
3.6 mm (0.142 in) —
3.7 mm (0.146 in) 4.2 mm (0.165 in)

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ISUZU KB P190 2007

UNIT REPAIR (AW30–40LE) 7A4–63
Forward Clutch Asseembly (C-1)
Disassembled View
RTW77ALF001001
EndOFCallout
Legend(1) Race
(2) Thrust bearing
(3) Oil seal ring
(4) Forward clutch drum
(5) O-ring
(6) Piston
(7) O-ring
(8) O-ring (9) Piston return spring
(10) Snap ring
(11) Race
(12) Thrust bearing
(13) Snap ring
(14) Flange
(15) Plate and disc Six plates and six discs
(16) Cushion plate

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ISUZU KB P190 2007

7A4–64 UNIT REPAIR (AW30–40LE)
Disassembly
Remove forward clutch assembly from direct clutch
assembly.
248RY00039
1. Place wooden blocks, etc. to prevent forward clutch shaft from touching the work stand, and place the
OD support on them.
Place the forward clutch onto the OD support and
remove the bearing and race.
248RY00048
2. Check piston stroke of forward clutch (C –1).
248R200008Using a dial indicator, measure the forward clutch
piston stroke by applying and releasing compressed
air (390 – 780 kPa or 57 – 114 psi) as shown.
Pack clearance: 0.6 – 1.0 mm (0.024 – 0.039 in)
3. Remove snap ring from clutch drum.
248RY00041
4. Remove the flange, disc and plate, and cushion plate.

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ISUZU KB P190 2007

UNIT REPAIR (AW30–40LE) 7A4–65
5. Place special tool on the spring retainer andcompress the return spring.
Using snap ring pliers, remove the snap ring.
Spring compressor : 5-8840-0254-0
248RY00003
6. Remove the piston return spring.
7. Place the forward clutch drum onto the OD suppor t. Holding the forward clutch piston by hand, apply
compressed air to the OD support to remove the
forward clutch piston.
248RY00042
8. Remove the O-rings from piston.
9. Remove the O-ring from forward clutch drum.
10. Remove the oil seal rings and thrust bearing from forward clutch drum.
Inspection and Repair
1. Check forward clutch pistonCheck that check ball is free by shaking the piston.
Check that the valve does not leak by applying
low-pressure compressed air.
248RY00031
2. Check forward clutch drum bushing. Using a dial indicator, measure the inside diameter
of the forward clutch drum bushing.
Maximum inside diameter: 24.08 mm (0.948 in) If the inside diameter is greater then the maximum,
replace the forward clutch drum.
248RY00043
3. Check disc, plate and flange. Check to see if the sliding surface of the disc, plate
and flange are worn or burnt. If necessary, replace
them.
 If the lining of the disc is peeling off or discolored,
or even if parts of the printed numbers are
defaced, replace all discs.

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ISUZU KB P190 2007