YH4
GRAND
VITARA
AUTOMATIC TRANSMISSION (4 A / T) 7B1-55
Check resultPossible cause
Line pressure higher
than standard level in
each rangeMalfunctioning regulator valve
Malfunctioning throttle valve
Maladjusted A / T throttle cable
Line pressure lower than
standard level in each
rangeDefective 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 ªDº
rangeFluid leakage from forward clutch
Defective O/D clutch
Leakage from ªDº range fluid pressure cir-
cuit
Line pressure lower than
standard level only in ªRº
rangeFluid leakage from direct clutch
Defective O/D clutch
Fluid leakage from reverse brake
Fluid leakage from ªRº range fluid circuit
Tightening torque of transmission case plug:
17 N.m (1.7 kg-m, 12.0 lb-ft)
STALL TEST
This test is to check overall performance of automatic transmission
and engine by measuring stall speed at ªDº and ªRº ranges. Be sure
to perform this test only when transmission fluid is at normal operat-
ing temperature and its level is between FULL and LOW marks.
CAUTION:
Do not run engine at stall more than 5 seconds continu-
ously, for fluid temperature may rise excessively high.
After performing stall test, be sure to leave engine running
at idle for longer than 30 seconds before another stall test.
1) Apply parking brake and block wheels.
2) Install tachometer.
3) Start engine with select lever shifted to ªPº.
4) Depress brake pedal fully.
5) Shift select lever to ªDº and depress accelerator pedal fully while
watching tachometer. Read engine rpm quickly when it has be-
come constant (stall speed).
6) Release accelerator pedal immediately after stall speed is
checked.
7) In the same way, check stall speed in ªRº range.
YH4
GRAND
VITARA
7B1-56 AUTOMATIC TRANSMISSION (4 A / T)
8) Stall speed should be within the following specification.
Stall speed: 2,100 ± 2,400 r / min. for G16 engine
2,300 ± 2,600 r / min. for J20 engine
2,300 ± 2,600 r / min. for H25 engine
Check result
Possible cause
Lower than standard
levelFaulty engine output
Defective torque converter
Higher than standard
level in ªDº rangeSlippery O/D clutch
Slippery forward clutch
Malfunctioning O/D one-way clutch
Malfunctioning one-way clutch No. 2
Low line pressure
Higher than standard
level in ªRº rangeSlippery direct clutch
Slippery reverse brake
Low fluid pressure
Slippery O/D clutch
Defective O/D one-way clutch
ROAD TEST
This test is to check if upshift and downshift take place at specified
speed while actually driving vehicle on a level road.
WARNING:
Carry out test in very little traffic area to prevent an acci-
dent.
Test requires 2 persons, a driver and a tester.
1) Warm up engine.
2) With engine running at idle, shift select lever ªDº.
3) Accelerate vehicle speed by depressing accelerator pedal grad-
ually.
4) While driving in ªDº range, check if gear shift occurs properly as
shown in Gear Shift Diagram in this section.
Test result
Possible cause
When 1 2 upshift fails to
occur1±2 shift valve stuck
When 2 3 upshift fails to
occur2±3 shift valve stuck
When 3 O/D upshift
fails to occur3±4 shift valve stuck
When gear shift point is in-
correctMaladjusted throttle cable
Defective shift solenoid valve
-A or -B
1±2, 2±3 or 3±4 shift valve not
operating properly
YH4
GRAND
VITARA
1
1. Shift solenoids connector
AUTOMATIC TRANSMISSION (4 A / T) 7B1-57
MANUAL ROAD TEST
This test check the gear being used in ªLº, ª2º or ªDº range when
driven with unoperated gear shift control system. Test drive vehicle
on a level road.
NOTE:
Before this test, check diagnostic trouble code (DTC).
1) Disconnect coupler of shift solenoid valves on transmission.
WARNING:
To avoid the danger of being burned, do not touch the hot
exhaust system when disconnecting shift solenoid
valves coupler.
2) With select lever in ªPº, start engine and warm it up.
3) With select lever in ªLº 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 acceler-
ate 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 with ignition switch OFF.
WARNING:
To avoid the danger of being burned, do not touch the hot
exhaust system when connecting shift solenoid valves
coupler.
7) Clear DTC with scan tool.
TIME LAG TEST
This test is to check conditions of clutch, reverse brake and fluid
pressure. ªTime lagº 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 re-
spectively, depress brake pedal.
2) Start engine.
3) With stop watch ready, shift select lever from ªNº to ªDº range
and measure time from that moment till shock is felt.
4) Similarly measure time lag by shifting select lever from ªNº to ªRº
range.
Specification for ªNºªDºLess than 1.2 sec.
time lagªNºªRºLess than 1.5 sec.
NOTE:
When repeating this test, be sure to wait at least minute
after select lever is shifted back to ªNº range.
Engine should be warmed up fully for this test.
Test resultPossible causes
When ªNºªDº time lag
exceeds specificationLow line pressure
Worn forward clutch
When ªNºªRº time lag
exceeds specificationLow line pressure
Worn direct clutch
Worn reverse brake
YH4
GRAND
VITARA
7C1
CLUTCH 7C1-1
GENERAL DESCRIPTION7C1 - 2 . . . . . . . . . . . . .
DIAGNOSIS7C1 - 3 . . . . . . . . . . . . . . . . . . . . . . . . . .
ON-VEHICLE SERVICE7C1 - 4 . . . . . . . . . . . . . . .
Clutch Pedal Height 7C1 - 4. . . . . . . . . . . . . . . . . .
Clutch Pedal Free Travel 7C1 - 4. . . . . . . . . . . . .
Clutch Fluid Pipe and Hose 7C1 - 4. . . . . . . . . . .
Clutch Master Cylinder 7C1 - 5. . . . . . . . . . . . . . .
Fluid Inspection 7C1 - 6. . . . . . . . . . . . . . . . . . . . .
Disassembly and Assembly
Clutch Master Cylinder 7C1 - 7. . . . . . . . . . . . . . Clutch Operating Cylinder 7C1 - 8. . . . . . . . . . . .
UNIT REPAIR7C1-10 . . . . . . . . . . . . . . . . . . . . . . . .
Clutch Cover, Clutch Disc and
Flywheel 7C1 - 10. . . . . . . . . . . . . . . . . . . . . . . . . .
TIGHTENING TORQUE
SPECIFICATIONS7C1-14 . . . . . . . . . . . . . . . . . . .
REQUIRED SERVICE MATERIALS7C1-14 . . . . .
SPECIAL TOOLS7C1-14 . . . . . . . . . . . . . . . . . . . . .
SECTION 7C1
CLUTCH
CONTENTS
YH4
GRAND
VITARA
1. Crankshaft
2. Flywheel
3. Clutch disc
4. Pressure plate
5. Clutch cover
6. Diaphragm spring
7. Release bearing
8. Input shaft bearing
9. Input shaft
10. Operating cylinder
11. Clutch housing
12. Release fork
7C1-2 CLUTCH
The clutch is a diaphragm-spring clutch of a dry single
disc type. The diaphragm spring is of a tapering-finger
type, which is a solid ring in the outer diameter part,
with a series of tapered fingers pointing inward.
The disc, carrying torsional coil springs, is positioned
on the transmission input shaft with an involute spline
fit.
The clutch cover is secured to the flywheel, and car-
ries the diaphragm spring in such a way that the pe-
ripheral edge part of the spring pushes on the pres-
sure plate against the flywheel (with the disc in be-
tween), when the clutch release bearing is held back.
This is the engaged condition of the clutch.Depressing the clutch pedal causes the release bear-
ing to advance and pushes on the tips of the tapered
fingers of the diaphragm spring. When this happens,
the diaphragm spring pulls the pressure plate away
from the flywheel, thereby interrupting the flow of
drive from flywheel through clutch disc to transmis-
sion input shaft.
GENERAL DESCRIPTION
YH4
GRAND
VITARA
CLUTCH 7C1-3
DIAGNOSIS
ConditionPossible CauseCorrection
SlippingImproper clutch pedal free travel.
Worn or oily clutch disc facing.
Warped disc, pressure plate or flywheel
surface.
Weakened diaphragm spring.
Master cylinder piston or seal cup not returning.Bleed air or replace master
cylinder.
Replace disc.
Replace disc, clutch cover or
flywheel.
Replace clutch cover.
Repair master cylinder.
Dragging clutchImproper clutch pedal free travel.
Weakened diaphragm spring, or worn spring tip.
Rusted input shaft splines.
Damaged or worn splines of transmission
input shaft.
Excessively wobbly clutch disc.
Clutch facings broken or dirty with oil.
Fluid leakage.Bleed air or replace master
cylinder.
Replace clutch cover.
Lubricate.
Replace input shaft.
Replace disc.
Replace disc.
Repair or replace.
Clutch vibrationGlazed (glass-like) clutch facings.
Clutch facings dirty with oil.
Release bearing slides unsmoothly on input
shaft bearing retainer.
Wobbly clutch disc, or poor facing contact.
Weakened torsion springs in clutch disc.
Clutch disc rivets loose.
Distorted pressure plate or flywheel surface.
Weakened or loosened engine mounting
bolt or nut.Repair or replace disc.
Replace disc.
Lubricate or replace input
shaft bearing retainer.
Replace disc.
Replace disc.
Replace disc.
Replace clutch cover or flywheel.
Retighten or replace mounting.
Noisy clutchWorn or broken release bearing.
Input shaft front bearing worn down.
Excessive rattle of clutch disc hub.
Cracked clutch disc.
Pressure plate and diaphragm spring rattling.Replace release bearing.
Replace input shaft bearing.
Replace disc.
Replace disc.
Replace clutch cover.
Grabbing clutchClutch disc facings soaked with oil.
Clutch disc facings excessively worn.
Rivet heads showing out of facing.
Weakened torsion springs.Replace disc.
Replace disc.
Replace disc.
Replace disc.
YH4
GRAND
VITARA
1. Clutch pedal
2. Clevis lock nut
3. Push rod
1. Clutch master cylinder
2. Clutch pipe
3. Clutch hose
4. Clutch operating cylinder
1. Pipe
2. Hose
3. Spanner
4. Flare nut wrench2, (a)
7C1-4 CLUTCH
ON-VEHICLE SERVICE
CLUTCH PEDAL HEIGHT
Adjust clutch pedal height by loosening clevis lock nut and turning
push rod as shown.
Clutch pedal height is normal if clutch pedal is about
20 mm (0.79 in.) higher than brake pedal.
After adjusting, tighten lock nut to specified torque.
Tightening Torque
(a): 10 N
.m (1.0 kg-m, 7.5 lb-ft)
CLUTCH PEDAL FREE TRAVEL
Depress clutch pedal, stop the moment clutch resistance is felt and
measure distance (clutch pedal free travel). Free travel should be
within following specification.
Pedal free travel ªaº: 15 ± 25 mm (0.6 ± 1.1 in.)
CLUTCH FLUID PIPE AND HOSE
REMOVAL
NOTE:
Do not allow fluid to get on painted surface.
1) Remove dust and dirt from each joint of hose and pipe to be dis-
connected and clean around reservoir cap.
2) Take out fluid with syringe or such.
3) Disconnect fluid pipe from hose.
NOTE:
To disconnect pipe from hose, separate them by using flare
nut wrench and spanner so as not to kink them.
YH4
GRAND
VITARA
1. Pipe
2. Hose
3. Flare nut
1. Pipe
2. Hose
3. Flare nut
4. E-ring
1. Master cylinder
assembly
2. Clutch pipe
3. Attaching nut
4. Attaching bolt
5. Clevis pin
6. Clip
7. Flare nut
CLUTCH 7C1-5
INSPECTION
Check pipe and hose for dent, kink, crack, dirt and dust. Replace
if check result is not satisfactory.
INSTALLATION
Reverse removal sequence noting following points.
Tighten flare nuts to specified torque.
Tightening Torque
(a): 16 N
.m (1.6 kg-m, 11.5 lb-ft)
NOTE:
For air bleeding of master cylinder alone, it must be removed
from vehicle.
(For procedures of removal and installation of master cylin-
der assembly and air bleeding, refer to CLUTCH MASTER
CYLINDER section.)
Do not allow fluid to get on painted surface.
Do not allow pipe and hose to contact hard against vehicle
or other parts.
Install each clamp securely.
Install E-ring securely as shown.
After installation, check clutch pedal free travel and bleed air
from system.
Check fluid leakage.
Add fluid close to MAX level of reservoir.
CLUTCH MASTER CYLINDER
REMOVAL
1) Clean around reservoir cap and take out fluid with syringe or
such.
2) Remove push rod clevis pin.
3) Disconnect fluid pipe from master cylinder.
NOTE:
Do not allow fluid to get on painted surfaces.
4) Remove master cylinder attaching nut and bolt.
5) Remove master cylinder assembly and gasket.