engine ACURA INTEGRA 1994 Service Repair Manual

Transmission Assembly
14. Install the intermediate shaft and the driveshafts(see section 16)-
NOTE: Replace the set rings with new ones.
Installation (cont'd)
-Sl
SET RINGReplace.
INTERMEDIATESHAFT
Replace.10 x 1.25 mm38 N.m (3.9 kgt m,28 tbtft)
15. Install the ball joints onto the lower arm (see sec-
tion 18).
16. Install the right damper fork (see section 18).
10 x 1.25 mm43 N.m {4.o ksf.m.32 lbf.ft)
RIGHTDAMPERFOBK
SELF.LOCKING NUTReplace.12 x 1.25 mm64 N.m {6.5 kgf.m,47 tbtft)
tLOWER ARM
:\
COTTER PIN
CASTLE NUT12 x 1.25 mm49 - 59 N.m 15.0 - 6.0 kgf m. Reptace.36 - 43 tbf.frl
13-44
DNIVESHAFTS
::.t
L
17. lnstall the exhaust pipe A, and the three way cat-
alytic converter (Bl8C'1 engine), and connect theheated oxygen sensor (HO2S) connector.
SELF-LOCKING NUTHO2SCONNECTORReplace.10 x 1.25 mm33 N.m (3.4 kgt.m,2s tbtftt
GASKETReplace.SELF.LOCKING NUTReplace.8 x 1.25 mm
SELF.LOCKING NUTReplace.THREE WAYCATALYTICCONVERTER1818C'l enginel
16 N'm 11.6 kgt m, 10 x 1 25 mm
l2tbt.ftl 54 N.m 15.5 kgt m,iro lbf.ftl
18. Install the engine splash shield.
GASKET

The Automatic Transmission is a combination of a 3-e,ement torque convefter and triple-shaft electfonically controlled
automatic transmission which provides 4 speeds forward and 1 speed reverse. The entire unit is positioned in line with
the engine.
Torque Converter, Gears and Clutches
The torque converter consists of a pump, turbine and stator assembly in a single unit, The torque converter is connected
to the engine crankshaft so they turn together as a unit as the engine turns. Around the outside of the torque converter
is a ring gear which meshes with the starter pinion when the engine is being staned. The entire torque converter assem-
bly serves as a flywheel while transmitting power to the transmission mainshaft.
The transmission has three parallel shafts, the mainshaft. countershaft and sub-shaft. The mainshatt is in line with the
engine crankshaft.
The mainshaft includes the clutches for 1 st, and 2ndl4th, and gears for 3rd. 2nd, 4th, reverse and l st (3rd gear is in-
tegral with the mainshaft, while reverse gear is integral with the 4th gear).
The countershaft includes the 3rd clutch and gears Ior 3rd, 2nd,4th, reverse, lst and parking. Reverse and 4th gears
can be locked to the countershaft at its center, providing 4th gear or reverse, depending on which way the selector is moved.
The sub-shaft includes the lst-hold clutch and gears for 1st and 4th
The gears on the mainshait are in constant mesh with those on the countershaft and sub-shaft. When certain combina-
tions of gears in the transmission are engaged by the clutches, power is transmitted from the mainshaft to the counter-
shaft via the sub-shatt to provide @, E, tr. tr and @ position.
Electronic Control
The electronic control system consists of the Transmission Control Module {TCM), sensors, and 4 solenoid valves. Shift-
ing and lock-up are electronically controlled for comfortable driving under all conditions.
The TCM is located below the dashboard, behind the left side kick panel on the driver's side.
Hydraulic Control
The valve bodies include the main valve body, secondary valve body, regulator valve body. servo body, and lock-up valve
body throuqh the respective separator plates.
They are bolted on the torque converter housing.
The main valve body contains the manual valve, 1-2 shift valve, 2-3 shift valve, Clutch Pressure Cont.ol (CPC) valve,
4th exhaust valve, relief valve, and oil pump gears.
The secondary valve body contains the 4-3 kick-down valve,3-2 kick-down valve,2-3 orifice cont.ol valve, 3-4 shitt
valve, orifice control valve. modulator valve, and servo control valve
The regulator valve body contains the pressure regulator valve. lock-up control valve, torque converter check valve, and
cooler check valve.
The servo bodv contains the servo valve which is integrated with the reverse shift fork, throttle valve B, and accumulators.
The lock-ug valve bodv contains the lock-up shift valve and lock-up timing B valve. and is bolted on the secondary valve
body.
Fluid from the regulator passes through the manual valve to the various control valves.
Shitt Control Mochanism
Input to the TCM i.om various sensors located throughout the car determines which shift control solenoid valve should
be activated.
Activating a shift control solenoid valve changes modulator pressure, causing a shift valve to move. This pressurizes
a line to one of the clutches. engaging that clutch and its corresponding gear.
Lock-up Mechanism
In @ position. in 2nd, 3rd and 4th, and E position in 3rd, pressurized tluid can be drained from the back of the tor-
que converter through an oil passage, causing the lock-up piston to be held against the torque converter cover. As this
takes Dlace, the mainshaft rotates at the same speed as the engine crankshatt. Together with hydraulic control, the TCM
optimizes the timing ol the lock-up mechanism.
The lock-up valves control the range of lock-up according to lock-up control solenoid valves A and B, and 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.
(cont'd)
14-3

Description
(cont'd)
Gear Selection
The selector lever has seven posirions; E PARK, E REVERSE, N NEUTRAL, @ 1st through 4th positions. E 1st
through 3rd positions, Ql2nd gear and [] 1st gear.
Starting is possible only in @ and I Oosition through use ot a slide-type, neutral-safety switch.
Automatic Tlansaxle {A/T) Gear Position Indicatol
A/T gear pos;tion indicator in the instrumenl panel shows what gear has been selected without having look down at
the console.
Position Description
l3?]] PARK Front wheels locked; parking pawl engaged with parking gear on countershatt. All clutches
reteaseo,
[R] REVERSE Reverse; reverse selector engaged with countershalt reverse gear and 4th clutch locked.
N NEUTRAL All clurches released.
D+l DRIVE General driving; starts off in 'lst, shifts automatically to 2nd, 3rd, then 4th, depending on vehicle
('lst through 4th) speed and throttle position. Do'vnshifts through 3rd, 2nd and 1st on deceleration to stop.
The lock-up mechanism comes into operation in 2nd, 3rd and 4th when the transmission in lDtposrtron.
Dgi DRIVE For rapid acceleration at highway speeds and general driving; starts off in 1st. shifts automatical-(1st through 3rd) ly to 2nd then 3rd, depending on vehicle speed and throttle position. Downshifts through lower
gears on deceleration to stop. The lock-up mechanism comes into operation in 3rd.
El SECOND Driving in 2nd geari stays in 2nd gear, does not shift up and down.
For engine braking or better traction starting off on loose or slippery surfece.
L]l FIRST Driving in 1st gear; stays in lst gear, does not shilt up.
For engine braking.
14-4

L!_j Position Deceleration
The power tlow when decelerating is as follows;
1. Rolling resistance lrom the road surface goes through the tront wheels to the final drive gear, then to the sub-shaft
1st gear via the 4th gear, and lst-hold clutch which is applied during deceleration.
2. The one-way clutch becomes free at this time because torque reverses.
3. The counterforce conveyed to the countershaft 4th gear turns the sub-shaft 4th gear via the mainshaft 4th gear.
At this time, since hydraulic pressure is also applied to the 1st clutch, counterfo.ce is also transmitted to the main-
shaft. As a result, engine braking can be obtained with lst gea.-
CLUTCH
SUB-SHAFT4TH GEARSUB-SHAFT 1ST GEARTOROUE CONVENTER
FINAL DRIVE
SUB'STIAFT
lST CLUTCH
MAINSHAFT
COUNTERSHAFT
REVEFSE SELECTOR HUB
REVERSE SELECTOR
(cont'dl
4TI1 GEAB
14-11

In [Q! or l!31 position. the optimum gear is automatically selected from 1st, 2nd, 3rd and 4th speeds, according to con-
ditions such as the balance between throttle opening (engine load) and vehicle speed.
D! or lE.l Position, lst speed
1. Hydraulic pressure is applied to the lst clutch. which rotates together with the mainshaft, and the mainshaft lst
gear rorares.
2. Power is transmitted to the countershaft 1st gear, and drives the countershaft via the one-way clutch.
3. Power is transmitted to the final drive gear and drives the final driven gear.
NOTE:
In lDil or [Dl]l position, hydraulic pressure is not applied to the 1st-hold clutch.
TOROUE CONVERTER
1ST CLUTCH
MAINSHAFT
COUNTERSHAFT
(cont'd)
FINAL DRIVE GEAR
FINAL DRIVEN GEAR
14-13

Description
Electronic Control System (cont'd)
. GRADE LOGIC CONTROL SYSTEM
How it works:
The TCM compares actual driving conditions with driving conditions memorized in the TCM. based on the input trom
the vehicle speed sensor, throttle position sensor, engine coolant temperature sensor, brake switch signal and select
lever position signal, to control shifting while a vehicle is ascending or descending a slope. or reducing speed.
SIGNALS DETECTED
Dliving ResistanceJudgement of Controlling Area
Engine Coolant
TemDerature Sensor
. Flat road mode. Asconding mode
(Fuzzy logic). Gradual Ascending
mode. Steep Ascending
14-20

. Ascending Contlol
When the TCM determines that the vehicle is climbing a hill in @ position, the system extends the engagement area
of 3rd gear to prevent the transmission Irom frequenrly shitting between 3rd and 4th gears, so the vehicle can run smooth
and have more power when needed.
NOTE: Shift schedules between 3rd and 4th gear are stored in the TCM to enable the transmission to automatically
select the most suitable gear according to the magnitude of a gradient by Fuzzy logic.
. Descending Control
When the TCM determines that the vehicle is going down a hill in @ position. the shift-up speed from 3rd to 4th gear
when the throttle is closed becomes taster than the set speed for tlat road driving to widen the 3rd gear driving area.
This, in combination with engine brake from the deceleration lock-up, achieves smooth driving when the vehicle is
descending.
There are two ascending modes with different 3rd gear driving areas according to the magnitude of a gradient stored in
the TCM.
When the vehicle is in 4th gear, and you are decelerating on a gradual hill, or when you are applying the brakes on a
steep hill, the transmission will downshitt to 3rd gear. When you accelerate the transmission will then return to 4th gear.
F
0
. Deceleration Control
Vohicle SDood
When the vehicle goes around a corner, and needs to decelerate first and then accelerate, the TCM sets the data for
deceleration control to reduce the number of times the transmission shifts to obtain smooth driving. When the vehicle
is decelerating from speeds above 27 mph (43 km/h). the TCM shifts the transmission from 4th to 3rd earlier than normal
to cope with upcoming acceleration to maintain smooth driving.
NOTE:
Fuzzy Logic: Fuzzy logic is a from at artificial intelligence that lets computers respond to changing conditions much like
a human mind would.
14-21

Hydraulic Control
The valve bodies include the main valve body, secondary valve body, regulator valve body, servo body and lock-up valve
body.
The oil pump is driven by splines behind the torque converter which is attached to the engine. Oil flows th.ough the
regulator valve to maintain specified pressure through the main valve body to the manual valve, directing pressure to
each of the clutches,
SHIFT CONTROL SOLEIIOIDVALVE ASSEMBLY
RTGHT SIDE COVER
LOCK.UP VALVE BODY
VALVE BODY
REGULATOR VBODY
SOLENOID VALVEASSEMBLY
4<.__i: )o.-
OIL PUMP GEARS
14-23

Rcgulator Valve
The r€gulator valve maintains a constant hydraulic pressure from the oil pump to the hydraulic control system, whil€
alEo furnishing oil to the lubricating system and torque convener.
Oil flows through B and B'. The oil which enters through B flows thfough the valve orifice to A, pushing the regulator
valve to the right. Acco.ding to the level of hydraulic pressure through B, the position of the valve changes, and the
amount of the oil thlough D from B'thus changes. This operation is continued. thus maintaining the line pressure.
IEI{GINE ]IIOT RUNNINGI{ENGINE RUNNING)
Siator Reaction Hydtaulic Pressure Control
Hydraulic pressure increase, according to torque, is performed by the regulator vslve using stator torque reaction. Thestator shaft is splined to the stator and its a.m end contacts the fegulator spring cap. When the car is accelerating orclimbing (Torque Convener Range). stator torque reaction acts on the stator shalt and the stator shaft arm pushes thersgulator spring cap in this - direction in proportion to the reaction. The spring compresses and the regulator valve movesto increase the regulated control pressure or line pressure. Line pressure is maximum when the stator reaction is maximum.
TOR VALVE
(cont'd)
From OIL PUMP
STATOR SHAFTSTATOR SHAFT ARM
14-25

E Position
As the engine turns, the oil pump also starts to operate. Automatic transmission fluid (ATF) is drawn from (99) and dis-
charged into (1 ). Then, ATF pressure is controlled by the regulator valve and becomes line pressure ( 1 ). The torque con-
verter inlet pressure (92) enters (94) of torque converter through the orifice and discharges into {90}.
The torque converter check valve prevents the torque converter pressure from rising'
Under this condition, the hydraulic pressure is not applied to the clutches.
NOTE:. When used, "left" or "right" indicates direction on the llowchart
. SOL-@: Shift Control Solenoid Valve A
' SOL{D:Shift Control Solenoid Valve B
. SOL@: Lock-up Control Solenoid Valve A
. SOL-@: Lock-up Control Solenoid Valve B
(cont'd)
14-29