AUTOMATIC TRANSMISSION (4 A/T) 7B1-3
General Description
Item Specifications
Torque
converterType 3-element, 1-step, 2-phase type (with TCC (lock-up) mechanism)
Stall torque ratio 2.0
Oil pump Type Trochoid type oil pump
Drive system Engine driven
Gear
change
deviceType Forward 4-step, reverse 1-step planetary gear type
Shift position“P” range Gear in neutral, output shaft fixed, engine start
“R” range Reverse
“N” range Gear in neutral, engine start
“D” range
(O/D ON)Forward 1st ↔ 2nd ↔ 3rd ↔ 4th (O/D)
automatic gear change
“D” range
(O/D OFF)Forward 1st ↔ 2nd ↔ 3rd
automatic gear change
“2” range (Normal mode) Forward 1st ↔ 2nd ← 3rd auto-
matic gear change
(Power mode) Forward 2nd ← 3rd automatic gear
change and fixed at 2nd gear
“L” range Forward 1st ← 2nd ← 3rd reduction, and fixed at
1st gear
Gear
ratio1st
(low gear)2.826
2nd
(second gear)1.493
3rd
(top gear)1.000
4th
(overdrive gear)0.689
Reverse
(reverse gear2.703
Control elements Wet type multi-disc clutch ... 3 sets
Wet type multi-disc brake ... 4 sets
One-way clutch ... 3 sets
Transfer Hi : 1.000
Lo : 1.816 (4WD model only)
Final gear reduction
ratio (Differential)5.125
Lubrication Lubrication system Force feed system by oil pump
Cooling Cooling system Radiator assisted cooling (water-cooled)
Fluid used
An equivalent of DEXRON
III
7B1-14 AUTOMATIC TRANSMISSION (4 A/T)
Diagnostic Trouble Code Table
Refer to the same item in Section 6-1.
Fail Safe Table
Refer to the same item in Section 6-1.
Visual Inspection
Visually check following parts and systems.
A/T Basic Check
This inspection is important for troubleshooting when PCM (ECM) has detected no DTC and no abnormality has
been noted in visual inspection. Follow flow table carefully.INSPECTION ITEM REFERRING SECTION
•A/T fluid - - - - - level, leakage, color SECTION 0B
•A/T fluid hoses - - - - - disconnection, looseness, deterioration SECTION 7B1
•Throttle (accelerator) cable - - - - - play, installation SECTION 6E2
•A/T throttle cable - - - - - play, installation SECTION 7B1
•A/T select cable - - - - - installation, operation SECTION 7B1
•Engine oil - - - - - level, leakage SECTION 0B
•Engine coolant - - - - - level, leakage SECTION 0B
•Battery - - - - - fluid level, corrosion of terminal
•Connectors of electric wire harness - - - - - disconnection, friction Section 6-1 or 7B1
•Fuses - - - - - burning SECTION 8
•Parts - - - - - installation, damage
•bolt - - - - - looseness
•Other parts that can be checked visually
•Also check following items at engine start, if possible.
–“O/D OFF” lamp - - - - - Operation SECTION 7B1
–“POWER” lamp - - - - - Operation SECTION 7B1
–Malfunction indicator lamp (“SERVICE ENGINE SOON” lamp) - -
- - - OperationSection 6-1
–Charge warning lamp - - - - - Operation SECTION 6H
–Engine oil pressure warning lamp - - - - - Operation SECTION 8C (SECTION 6A2 for pres-
sure check)
–Engine coolant temp. meter - - - - - Operation
–Other parts that can be checked visually
Step Action Yes No
1Was “AUTOMATIC TRANSMISSION DIAGNOSTIC
FLOW TABLE” performed?Go to Step 2. Go to “AUTOMATIC
TRANSMISSION DIAG-
NOSTIC FLOW TABLE”.
2Perform “MANUAL ROAD TEST” in this section.
Is it OK?Go to Step 3. Go to Step 4.
3Proceed to “TROUBLE DIAGNOSIS TABLE 1” in this
section.
Is trouble identified?Repair or replace
defective parts.Go to Step 5.
AUTOMATIC TRANSMISSION (4 A/T) 7B1-15
Trouble Diagnosis Table 1
Trouble Diagnosis Table 2
TRANSMISSION FLUID
RUNNING CONDITION
4 Perform stall test, time rag test, line pressure test,
engine brake test and “P” range test referring to
“STALL TEST”, “LINE PRESSURE TEST”, “ENGINE
BRAKE TEST” and ““P” RANGE TEST” in this section.
Are the test results satisfactory?Go to Step 5. Proceed to “TROUBLE
DIAGNOSIS TABLE 3” in
this section.
5 Proceed to “TROUBLE DIAGNOSIS TABLE 2” in this
section.
Is trouble identified?Repair or replace
defective parts.Proceed to “TROUBLE
DIAGNOSIS TABLE 3” in
this section. Step Action Yes No
Condition Possible Cause Correction
TCC does not operateBrake pedal (stop lamp) switch or its circuit
faulty (H25 engine only)Refer to “DIAGNOSTIC FLOW
TABLE A-1” in this section.
4WD low switch or its circuit faulty
Engine coolant temp. sensor or its circuit faulty
Cruise control signal circuit faulty (if equipped)
Gear does not change
to 4thO/D off switch or its circuit faulty Refer to “DIAGNOSTIC FLOW
TABLE A-2” in this section.
4WD low switch or its circuit faulty
Engine coolant temp. sensor or its circuit faulty
Cruise control signal circuit faulty (if equipped)
Condition Possible Cause Correction
Low fluid pressureClogged oil pump strainer Wash strainer.
Malfunction of pressure regulator valve Overhaul valve body.
High fluid pressurePressure regulator valve Overhaul valve body.
Condition Possible Cause Correction
Unable to run in all
rangeRegulator valve stick Replace.
Clogged oil strainer Wash strainer.
Seized or broken planetary gear Repair or replace.
Faulty manual valve Replace.
Poor 1st speed run-
ning or excessive slip-
page in “D” or “2”Faulty 1–2 shift valve Replace.
AUTOMATIC TRANSMISSION (4 A/T) 7B1-39
Line Pressure Test
Purpose of this test is to check operating conditions of each part
by measuring fluid pressure in fluid pressure line. Line pressure
test requires following conditions.
•Automatic fluid is at normal operating temperature (70 to 80
°
C/158 – 176 °F).
•Fluid is filled to proper level (between FULL HOT and LOW
HOT on dipstick).
1) Apply parking brake securely and place checks against
wheels.
2) Attach oil pressure gauge to fluid pressure check hole (1) in
transmission case.
Special tool
(A) : 09925-37811-001
3) Depress foot brake fully, run engine at idle and stall.
4) Check fluid pressure in “D” or “R” range within the following
specification.
Line pressure :
5) If check result is OK, disconnect special tool, then tighten
transmission case plug to specified torque.
Tightening torque
Transmission case plug : 17 N·m (1.7 kg-m, 12.0 lb-ft) CAUTION:
After attaching oil pressure gauge, check that not fluid
leakage exists.
CAUTION:
Do not continue running engine at stall speed longer
than 5 seconds.
“D” range“R” range
Idle speed
4.1 – 4.6 kg/cm
2
58 – 65 psi5.4 – 6.0 kg/cm
2
77 – 85 psi
Stall speed
12.0 – 13.5 kg/cm
2
171 – 192 psi14.6 – 17.1 kg/cm
2
208 – 243 psi
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
7B1-44 AUTOMATIC TRANSMISSION (4 A/T)
LEVEL CHECK AT ROOM TEMPERATURE
The fluid level check at room temperature (20 – 30 °C (68 – 86
°F)) performed after repair or fluid change before test driving is
just preparation for level check of normal operating temperature.
The checking procedure itself is the same as that described previ-
ously. If the fluid level is between FULL COLD and LOW COLD,
proceed to test drive. And when the fluid temperature has
reached the normal operating temperature, check fluid level again
and adjust it as necessary.
Fluid change
1) Lift up vehicle.
2) With engine is cool, remove drain plug (1) from oil pan and
drain A/T fluid.
3) Install drain plug (1).
Tightening torque
A/T fluid drain plug (a) :
23 N·m (2.3 kg-m, 17.0 lb-ft)
4) Lower vehicle and fill proper amount of an equivalent of
DEXRON
®-III.
5) Check fluid level referring to “LEVEL CHECK NORMAL
OPERATING TEMPERATURE” of “FLUID LEVEL” in this
section.
Fluid specification :
An equivalent of DEXRON
®-III
Fluid capacity
When draining from drain plug hole:
2.5 liters (5.28/4.40 US/lmp.pt.)
When overhauling:
6.8 liters (14.37/11.97 US/lmp.pt.)
7B1-58 AUTOMATIC TRANSMISSION (4 A/T)
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 primary regulator valve sleeve so that its tip is posi-
tioned as it was before disassembly.
•Use new TCC (lock-up) control valve gasket, solenoid gas-
ket and lower valve body plate gasket.
•Tighten shift solenoid valve bolt to specified torque.
Tightening torque
Shift solenoid valve bolt : 10 N·m (1.0 kg-m, 7.5 lb-ft)
Name of spring Outer diameter Free length
Pressure relief valve spring 13.14 mm (0.517 in.) 32.14 mm (1.265 in.)
TCC (Lock-up) control valve
spring11.40 mm (0.449 in.) 32.60 mm (1.283 in.)
Valve damping spring 4.95 mm (0.195 in.) 20.00 mm (0.787 in.)
Low coast modulator valve spring 10.00 mm (0.394 in.) 42.35 mm (1.667 in.)
Inter coast modulator valve
spring9.04 mm (0.356 in.)
(G16 and J20 engines)27.26 mm (1.073 in.)
(G16 and J20 engines)
10.00 mm (0.394 in.)
(H25 and H27 engine)25.60 mm (1.008 in.)
(H25 and H27 engine)
Ball valve spring 10.5 mm (0.413 in.) 13.7 mm (0.539 in.)
Bypass valve spring 13.82 mm (0.544 in.) 28.90 mm (1.138 in.)
Primary regulator valve spring 17.02 mm (0.670 in.) 50.28 mm (1.980 in.)
1. Solenoid valve No. 1 (Shift solenoid valve)
2. Low coast modulator valve spring
3. Inter coast modulator valve spring
4. Intermediate coast modulator valve
5. Low coast modulator valve
7B1-60 AUTOMATIC TRANSMISSION (4 A/T)
Accumulator piston and spring specification :
Tightening Torque Specification
Used forPiston outer
diameter “a”Spring free length “b”
Direct clutch accumulator (2)31.80 – 31.85 mm
(1.252 – 1.254 in.)Upper spring 43.56 mm (1.715 in.)
Lower spring 30.00 mm (1.181 in.)
Forward clutch accumulator (1)31.80 – 31.85 mm
(1.252 – 1.254 in.)Upper spring 57.18 mm (2.251 in.)
Lower spring 30.50 mm (1.201 in.)
Second brake accumulator (3)34.80 – 34.85 mm
(1.370 – 1.372 in.)Upper spring 56.16 mm (2.211 in.)
Lower spring 18.5 mm (0.728 in.)
Fastening partTightening torque
Nm kg-m lb-ft
Automatic transmission fluid drain plug 23 2.3 17.0
Transfer oil level/filler and drain plugs 23 2.3 17.0
Transmission case plug 17 1.7 12.5
Manual select lever nut 13 1.3 9.5
Manual select cable nut 7 0.7 5.5
Manual selector assembly bolts 18 1.8 13.5
Transmission to engine bolts and nuts 85 8.5 61.5
Engine rear mounting bolts
Engine rear mounting member bolts50 5.0 36.5
Universal joint flange bolts and nuts 50 5.0 36.5
Torque converter mounting bolts 65 6.5 47.0
Adapter case or extension case bolts 42 4.2 30.0
Transmission range switch lock bolt 5.5 0.55 4.0
Oil pipe union bolts 35 3.5 22.5
Drive plate bolts 78 7.8 56.5
Interlock cable clamp screw 2.2 0.22 1.5
Interlock cable outer mounting nut 13 1.3 9.5