1998 ACURA INTEGRA Service Repair Manual

Iznd Goar
The ftow ot fluid up the 1-2 shift valve is the same 8s in 1st gear. As the speed of the vehicle reaches the prescriabed
value, the shift control solenoid valve A is turned ON by means of the TCM. As a result, the 1-2 shift valve is moved to
the left and uncovers the port leading to the 2nd clutch; the 2nd clutch is engaged.
Fluid flows by way of:- Line pressure (4) -r 1-2 Shift Valve i 2-3 Shift Valve - znd Clutch Pressure (21) i 2nd Cluch
The hydraulic pressure also flows to the lst clutch. However, no pow€r is transmitted because ofthe one-way clutch.
NOTE: When used, "Ieft" or "right" indicates ditection on the hydraulic circuit.
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Description
Hydraulic Flow (cont'dl
3rd Gear
The flow of fluid up to the 1-2 and 2-3 shift valve is the same as in 2nd gear. As the speed of the vehicle reaches theprescribed value. the shift control solenoid valve B is turned OFF (shift control solenoid valve A remains ON). The 2-3
shift valve is then moved to the left, uncovering the port leading to the 3rd clutch. Since the 3-4 shift valve is moved
to the right to vover the port to the 4th clutch, the 3rd clutch is turned on.
Fluid flows by way of:- Line pressure (4) rj) 1-2 Shift Valve + 2-3 Shift Valve - 3rd Clutch Pressure (31) r 3-4 Shift Valve(not controlledl - 3rd Clutch Pressure (30) + 3rd Clutch
The hydraulic pressure also flows to the lst clutch. However, no power is transmitted because of the one-way clutch
as in the 2nd gear.
NOTE: When used, "|eft" or "right" indicates direction on the hydraulic circuit.
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Iq1 Position
4. 4th Gear
The flow of fluid up to the 1-2, 2-3 and 3-4 shift valves is the same as in 3rd gear. As the speed of the vehicle reaches
the prescribed value, the shift control solenoid valve A is turned OFF (shift control solenoid valve B remains OFF). As
this takes place, 3-4 shitt valve is moved to the left and uncovers the port leading to the 4th clutch. Since thel-2 and 2-
3 shift valves are kept on the left side, the fluid flows through the 4th clutch; the power is transmitted through the 4th
clutch.
Fluid flows by way of:- Line pressure (4) + 1-2 Shift Valve ) 2-3 Shift Valve - 3rd Clutch Pressure (3'1) -t 3-4 Shift Valve -
4th Clutch pressure (41) + Manual Valve - 4th Clutch Pressure (40) + 4th Clutch
The hvdraulic pressure also flows to the 1st clutch, However, no power is transmitted because of the one-way clutch
as in 2nd and 3rd gears.
NOTE: When used, "1eft" or "right" indicates direction on the hydraulic circuit.
I
T(cont'd)
14-35

Description
Hydraulic Flow (cont'dl
lll Position
The flow of fluid th.ough the torque converter circuit is the same as in S postion. The line pressure (1) tlows through themanual valve and becomes line pressure (3). lt then flows through the 1-2 shift valve to the servo valve via the servo con-trol valve, causing the shift fork shaft to be moved in the reverse direction.
Under this condition, the shift control solenoid valve A is turned ON whereas the valve B is turned OFF as in 3rd gear in
E ot O"- position. As a result. the 1-2 shift valve is also moved to the left. The fluid (3') will flow through tne servo varve
and manual valve to the 4th clutch; power is transmitted through the 4th clutch.
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E Position
The flow of tluid through the torque converter circuit is the same as in L\l]position. The line pressure (1) becomes line
pressure (3) as it passes through the manual valve. Then line pressure (3) flows through the 1-2 shift valve to the servo
valve via the servo control valve, causing the shift fork shaft to be moved to the reverse position as in @ position.
However, the hydraulic pressure is not supplied to the clutches. Power is not transmitted.
NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.
14-37

Description
Lock-up System
Lock-up Clutch
1. Operation (clutch on)
With the lock-up clutch on, the fluid in the chamber between the torque converter cover and lock-up piston is discharged,
and the converter fluid exerts pressure through the piston against the converter cover, As a result, the converter turbine islocked on the converter cover firmly. The effoct is to bypass the converter, thereby placing the vehicle in direct drive.
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The power flows by way of:
Engine
I
Drive plate
I
Torque converter
I
Lock-up piston
I
Damper spring
I
Turbine
I
Mainshatt
2. Operation (clutch otl)
With the lock-up clutch oft, the tluid flows in the reverse of "clutch on." As a result, the lock-up piston is moved away
from the converter cover; that is, the torque converter lock-up is released.
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Engine
I
Drive plate
I
Torque converter cover
I
Pump
I
Turbine
Mainshaft
LOCK-UP PISTON
TOROUE CONVERTERCOVER
:1
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TURBINE
tl
u
v

In E position in 2nd, 3rd and 4th, and E position in 3rd, pressurized fluid is drained from rhe back of the torque con-
verter through a fluid passage, causing the lock-up piston to be held against the torque converter cover. As this takes
place, the mainshaft rotates at the same speed as the engine crankshatt. Together with hydraulic control, the TCM op-
timized the timing of the lock-up system. Under certain conditions, the lock-up clutch is applied during deceleration in
3rd and 4th gear.
The lock-up system controls the range of lock-up according to lock-up control solenoid valves A and B, and the throttle
valve B. When lock-up control solenoid valves A and B activate, modulator pressure changes. Lock-up control solenoid
valves A and B are mounted on the torque converter housing. and are controlled by the TCM.
LOCK,UP CONTROL
LOCT.UP SHIfT VALVE
AlF COOIER
tocK uP coNTno! valvE
Solenoid valve
L*r""r "o.Jtio" \B
Lock'up OFFOFFOFF
Lock-up, slightONOFF
Lock-up, halfONON
Lock-up, fullONON
LOCK-Updu.ing decelerationONDuty operationOFF - ON
IOCK UP TIMING B VATVE
(cont'd)
14-39

Description
LOC(,UP SlllFT VATVE
Lock-up System (cont'd)
No Lock-ug
The pressurized fluid regulated by the modulator works on both ends of the lock-up shift valve and on the left side ot
the lock-up control valve. Under this condition, the pressures working on both ends of the lock-up shift valve are equal.
the shift valve is moved to the right side by the tension of the valve spring alone. The tluid from the ATF pump will llow
through the left side of the lock-up clutch to the torque converter; that is, the lock-up clutch is in OFF condition.
NOTE: When used, "left" or "right" indicates direction on the hydraulic circuit.
LOCX.UP CONTROI
LOCK.UP COITTFOT VATVE
MOOUTATOR PRESSURE
i
il
rl
I
IOCK IJP TIMING B VALVE
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