Page 449 of 656

7B1-40 AUTOMATIC TRANSMISSION (4 A/T)
TROUBLESHOOTING
Road Test
This test is to check if upshift and downshift take place at specified speed while actually driving vehicle on a
level road.
1) Warm up engine.
2) With engine running at idle, shift select lever “D”.
3) Accelerate vehicle speed by depressing accelerator pedal gradually.
4) While driving in “D” range, check if gear shift occurs properly as shown in “GEAR SHIFT DIAGRAM” in this
section.
TROUBLESHOOTING
Condition Possible cause
Line pressure higher than standard level in each
range•Malfunctioning regulator valve
•Malfunctioning throttle valve
•Maladjusted A/T throttle cable
Line pressure lower than standard level in each
range•Defective O/D clutch
•Defective oil pump
•Malfunctioning throttle valve
•Malfunctioning regulator value
•Maladjusted A/T throttle cable
Line pressure lower than standard level only in
“D” range•Fluid leakage from forward clutch
•Defective O/D clutch
•Leakage from “D” range fluid pressure circuit
Line pressure lower than standard level only in
“R” range•Fluid leakage from direct clutch
•Defective O/D clutch
•Fluid leakage from reverse brake
•Fluid leakage from “R” range fluid circuit
WARNING:
Carry out test in very little traffic area to prevent an accident.
Test requires 2 persons, a driver and a tester.
Condition Possible cause
When 1 → 2 upshift fails to occur 1–2 shift valve stuck
When 2 → 3 upshift fails to occur 2–3 shift valve stuck
When 3 → O/D upshift fails to occur 3–4 shift valve stuck
When gear shift point is incorrect•Maladjusted throttle cable
•Defective shift solenoid valve -A or -B
•1–2, 2–3 or 3–4 shift valve not operating properly
Page 450 of 656

AUTOMATIC TRANSMISSION (4 A/T) 7B1-41
Manual Road Test
This test check the gear being used in “L”, “2” or “D” range when
driven with unoperated gear shift control system. Test drive vehi-
cle on a level road.
1) Disconnect shift solenoid coupler (1) valves on transmission.
2) With select lever in “P”, start engine and warm it up.
3) With select lever in “L” range, start vehicle and accelerate to
20 km/h (12.5 mile/h). Check in this state that 1st gear is
being used.
4) At 20 km/h (12.5 mile/h), shift select lever to “2” range and
accelerate to 40 km/h (25 mile/h). Check in this state that 3rd
gear is being used.
5) At 40 km/h (25 mile/h), shift select lever to “D” range and
check that O/D gear is used when speed is higher than 40
km/h (25 mile/h).
6) After above checks, stop vehicle then engine, and connect
shift solenoids coupler (1) with ignition switch OFF.
7) Clear DTC with scan tool.
Time Lag Test
This test is to check conditions of clutch, reverse brake and fluid pressure. “Time lag” means time elapsed since
select lever is shifted with engine idling till shock is felt.
1) With chocks placed before and behind front and rear wheels respectively, depress brake pedal.
2) Start engine.
3) With stop watch ready, shift select lever from “N” to “D” range and measure time from that moment till shock
is felt.
4) Similarly measure time lag by shifting select lever from “N“ to “R” range.
Specification for time lag :NOTE:
Before this test, check diagnostic trouble code (DTC).
WARNING:
To avoid the danger of being burned, do not touch the hot
exhaust system when disconnecting shift solenoid cou-
pler (1).
WARNING:
To avoid the danger of being burned, do not touch the hot
exhaust system when connecting shift solenoid coupler
(1).
“N” →
→→ → “D”Less than 1.2 sec.
“N” →
→→ → “R”Less than 1.5 sec.
Page 451 of 656

7B1-42 AUTOMATIC TRANSMISSION (4 A/T)
TROUBLESHOOTING
Engine Brake Test
1) While driving vehicle in 3rd gear of “D” range, shift select lever down to “2” range and check if engine brake
operates.
2) In the same way as in step 1, check engine brake for operation when select lever is shifted down to “L”
range.
3) If engine brake fails to operate in above tests, possible causes for such failure are as follows. Check each
part which is suspected to be the cause.
TROUBLESHOOTING
“P” Range Test
1) Stop vehicle on a slope, shift select lever to “P” range and at the same time apply parking brake.
2) After stopping engine, depress brake pedal and release paring brake.
3) Then, release brake pedal gradually and check that vehicle remains stationary.
4) Depress brake pedal and shift select lever to “N” range.
5) Then, release brake pedal gradually and check that vehicle moves.NOTE:
When repeating this test, be sure to wait at least minute after select lever is shifted back to “N”
range.
Engine should be warmed up fully for this test.
Condition Possible cause
When “N” → “D” time lag exceeds specification•Low line pressure
•Worn forward clutch
When “N” → “R” time lag exceeds specification•Low line pressure
•Worn direct clutch
•Worn reverse brake
WARNING:
Before test, make sure that there is no vehicle behind so as to prevent rear-end collision.
Condition Possible cause
Fails to operate when shifted down to “2” range Second coast brake defective
Fails to operate when shifted down to “L” range Reverse brake defective
WARNING:
Before test, check to make sure no one is around vehicle or down on a slope and keep watchful for
safety during test.
Page 460 of 656
AUTOMATIC TRANSMISSION (4 A/T) 7B1-51
DISASSEMBLY
1) After removing retaining ring (1), remove direct clutch input
hub (2) and forward clutch hub (3).
2) Remove bearing race and thrust bearing.
3) Install direct clutch input hub (1) and retaining ring (2).
4) Install forward clutch (2) to O/D case (1). Apply 4 – 8 kg/cm
2
air pressure into fluid hole at the right of cut in O/D case and
measure movement of forward clutch piston.
If measured value is not within standard range, use either
1.8 mm (0.071 in.) or 2.0 mm (0.079 in.) clutch disc to adjust
it to standard value.
Standard forward clutch piston movement :
1.40 – 1.70 mm (0.056 – 0.067 in.)
1. Thrust bearing No. 2
2. Thrust forward clutch bearing
3. Thrust rear race
Page 461 of 656
7B1-52 AUTOMATIC TRANSMISSION (4 A/T)
5) Remove retaining ring (1) and then remove direct clutch
input hub.
6) Remove retaining ring and then remove all clutch discs.
7) Using special tool and hydraulic press, compress forward
clutch piston return spring and remove retaining return
spring.
Special tool
(A) : 09926-98310
8) Remove forward clutch piston return spring.
9) Install forward clutch to O/D case. Blow low pressure air into
fluid hole at the right of cut in O/D case to remove forward
clutch piston.
CAUTION:
Be careful when applying pressure, for overpressure will
cause plate section of piston return spring to deform.
Page 462 of 656

AUTOMATIC TRANSMISSION (4 A/T) 7B1-53
DIRECT CLUTCH
DISASSEMBLY
1) Install direct clutch assembly (1) to center support (2) and
with 4 – 8 kg/cm
2 air pressure applied to second fluid hole
from the left, measure stroke of direct clutch piston as shown
in figure.
If it is not within standard range, use 3.55 mm, 3.75 mm or
4.0 mm (0.140 in., 0.147 in. or 0.157 in.) clutch backing plate
to adjust it to standard stroke.
Standard direct clutch piston stroke :
0.90 – 1.30 mm (0.035 – 0.051 in.)
2) Remove direct clutch assembly from center support and
then remove retaining ring.
3) Remove clutch backing plate (1) and then remove clutch
disc (3) and clutch plate (2).
4) Using special tool and hydraulic press (1), compress direct
clutch piston return spring (3) and remove retaining return
spring ring (2).
Special tool
(A) : 09926-98310
5) Remove direct clutch piston return spring.
CAUTION:
Be careful when applying pressure, for overpressure will
cause plate section of piston return spring to deform.
Page 463 of 656

7B1-54 AUTOMATIC TRANSMISSION (4 A/T)
6) Install direct clutch cylinder to center support.
Remove direct clutch piston by blowing air into the second
hole from the left as shown in the figure. Also, remove direct
clutch inner piston by blowing air into hole at the extreme
right. And then remove O-rings from pistons.
Front upper valve body
ASSEMBLY
Assemble each component by reversing disassembly procedure
and noting the following points.
•Coil outer diameter and free length of each valve spring
should be as listed below. Be sure to use each one of correct
size.
Coil outer diameter and free length of each valve spring
•Install as many throttle valve compensating rings as written
down when disassembled.
•Tighten throttle cam bolt (1) to specified torque.
Tightening torque
Throttle cam bolt (a) : 7.5 N·m (0.75 kg-m, 5.5 lb-ft)
•Tighten pressure relief valve bolts (1) to specified torque.
Tightening torque
Pressure relief valve bolt (b) : 5.5 N·m (0.55 kg-m, 4.0 lb-ft)
Name of spring Outer diameter Free length
Secondary regulator
valve spring17.43 mm
(0.681 in.)71.27 mm
(2.806 in.)
Cut back valve spring 6.85 mm
(0.259 in.)23.0 mm
(0.906 in.)
Throttle valve
secondary spring8.56 mm
(0.337 in.)18.86 mm
(0.743 in.)
Throttle valve
primary spring10.90 mm
(0.429 in.)39.55 mm
(1.557 in.)
Page 464 of 656
AUTOMATIC TRANSMISSION (4 A/T) 7B1-55
LOWER VALVE BODY
1. Lower valve body 7. TCC (Lock-up) control valve plate 13. Primary regulator valve sleeve
2. Spring 8. TCC (Lock-up) control valve gasket 14. Primary regulator valve plunger
3. Pressure relief valve ball 9. TCC (Lock-up) control sleeve 15. Primary regulator valve
4. Pressure relief valve retainer 10. TCC (Lock-up) control valve 16. Spacer
5. Lower valve body plate 11. Pin
6. Lower valve body gasket 12. Retainer