Description
The automatic transmission is a 3-element torque converter and a dual-shaft electronically controlled unit which provides
4 soeeds forward and 1 reverse.
Torque Convertel, Geats, and Clutches
The torque converter consists of a pump, turbine and stator, assembled in a single unit. They are 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 started. The entire torque converter assembly seryes as a
flywheel while transmiuing power to the transmission mainshaft.
The transmission has two parallel shafts: the mainshaft and the countershaft. The mainshaft is in Iine with the engine
crankshaft. The mainshaft includes the 1st, 2nd and 4th clutches, gears tor 2nd, 4th, reverse and lst (3rd gear is integral
with the mainshaft, while the reverse gear is integral with the 4th gear). The countershaft includes the 3rd clutch, and
gears for 3rd,2nd, 4th, reverse. 1st and park. The gears on the mainshaft are in constant mesh with those on the counter-
shaft. When certain combinations of gears in transmission are engaged by clutches. power is transmitted from the main-
shaft to the countershaft to provide E, ld, E, and E positions.
Electronic Control
The electronic control svstem consists of the Powertrain Control Module {PCM), sensors, a linear solenoid and four
solenojd valves. Shifting and lock-up are electronically controlled for comtonable driving under all conditions. The PCM is
located below the dashboard, under the front lower panel on the passenger's side
Hydraulic Control
The valve bodies include the main vatve body, the secondary valve body, the regulator valve body, the servo body and the
lock-up valve body through the respective separator plates, They are bolted on the torque converter housang
The main valve body contains the manual valve, the 1-2 shift valve. the 2nd orifice control valve, the CPB {Clutch Pressure
Back-up) valve, the modulator valve. the servo control valve, the relief valve, and ATF pump gears The secondary valve
body contains the 2-3 shift valve. the 3-4 shift valve, the 3-4 orifice control valve, the 4th exhaust valve and the CPC (Clutch
pressure Control) valve. The regulator valve body contains the pressure regulator valve, the torque converter check valve,
the cooler relief valve, and the lock-up control valve. The servo body contains the servo valve which is integrated with the
reverse shift fork, and the accumulators. The lock-up valve body contains the lock-up shift valve and the lock-up timing
valve. The linear solenoid and the shift control solenoid valve Ay'B are bolted on the outside of the transmission housing,
and the lock-up control solenoid valve Ay'B is bolted on the outside of the torque converter housing. Fluid from regulator
passes through the manual valve to the various control valves. The clutches receive fluid from their respective teed pipes
or internal hydraulic circuit.
Shift Control Mechanism
Input from various sensors located throughout the car determines which shift control solenoid valve the PCM will activate
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, The shift control solenoid valves A and B are con-
trolled by the PCM.
Lock-up Mechanism
In ,Dt1 position, in 3rd and 4th. and in E position in 3rd, pressurized fluid is drained from the back of the torque converter
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 as the engine crankshaft. Together with hydraulic control, the PCM optimizes the timing of
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 linear solenoid. When lock-up control solenoid valves A and B activate, the modulator pressure changes The lock-
up control solenoid valves A and B and the linear solenoid are controlled by the PCM.
(cont'd)
14-3
\
@ Position
As the engine turns, the ATF pump also starts to operate, Automatic transmission fluid (ATF) is drawn from (99) and dis-
charged into (1). Then, ATF flowing from the ATF pump becomes the line pressure (1). The line pressure (1) is regulated
by the regulator valve. The torque conv€rter inlet pressure (92) enters (94) of the torque converter through the lock-up
shift valve and discharges into (901. The torque converter ch€ck valve prevents the torque converter pressure from rising'
Under this condition, the hydraulic pressure is not applied to the clutches'
NOTE: When used, "1eft" or "right" indicates direction on the hydraulic circuit'
14-25
Mai nshaft/Cou ntershaft
Linear Solenoid AssemblySpeed Sensors
Replacement
1. Remove the mounting bolts and the linear solenoid
assemory.
Clean the mounting surfaceand flu id passages.
6x1.0mm12 N.m 11.2 kgl m,8.7 tbf.ftl
@
@
GASKET
Clean the mounting surface and fluid passage of the
linear solenoid assembly and transmission housing.
Install a new linear solenoid assembly with a new
gasl(et.
NOTE; Do not pinch the gasket when installing the
linear solenoid; make sure that the gasket is installedproperly in the mounting groove of the linear sole-
noid.
Check the linear solenoid connector for rust, dirt or
oil, and connect it securely,
LINEARSOLENOIDASSEMELY
I
14-108
Replacement
't.
6x128.7
Remove the 6 mm bolt and the countershaft speed
sensor from the right side cover.
COUNTERSI{AFTSPEED SENSOR
O.RINGReplace.
MAINSHAFTSPEEDSENSOR
MAINSHAFT SPEEDSENSOB WAS}IER(D16Y7 enginel
6x1.0mm12 N.m (1.2 kgf m,8.7 tbf.ft)
1.0 mmN.m (1.2 kgf.m,rbf ft)
\\
/,
%/E:)
Remove the 6 mm bolt and the mainshaft sDeed
sensor from the transmission housino.
Replace the O-ring with a new one before installing
the countershaft speed sensor or th€ mainshaft speed
sensor.
NOTE: Installthe mainshaft speed sensor washer on
the mainshaft speed sensor. The mainshaft speed
sensor washer is used on models with the D'|6Y7
engine.
Symptom-to-Component Chart
Hydraulic System (cont'dl
G.
n,
set idle rpm in gear to specified idle speed. lf still no good, adjust motor mounts as outlined in enginesection of this manual.
lf the clutch pack is seized or is excessively worn. inspect the other clutches for wear, and check the orificecontrol valves, CPC valve and linear solenoid for free movement.
lf the linear solenoid is stuck, inspect the clutches for wear.
lmproper alignment or main valve body and torque converter housing may cause ATF pump seizure. Thesymptoms are mostly an rpm-related ticking noise or a high-pitched squeak.
lf the l st clutch feed pipe guide in the end cover is scored by the mainshaft, inspect the ball bearing forexcessive movement in the transmission housing. lf oK, replace the end cover as it is dented. The o-rinounder the guide is probably worn.
Replace the mainshaft if the bushing for the 4th feed pipe is loose or damaged. lf the 4th feed pipe is danFaged or out of round, replace the right side cover.
Replace the mainshaft if the bushing for the 1st feed pipe is loose or damaged. lf the 1st feed pipe is darn-aged or out of round, replace it.
A worn or damaged sprag clutch is mostly a result of shifting the transmission inthe wheels rotate in reverse, such as rocking the vehicle in snow.
or E position while
Inspect for damage and wear:
1. Reverse selector gear teeth chamfers.
2. Engagement teeth chamfers of countershaft 4th and reverse gear.
3. Shift fork for scuff marks in center.
4. Differential pinion shaft for wear u nder pin ion gears.
5. Bottom of 3rd clutch for swirl marks.
Replace items 1,2,3 and 4 if worn or damaged. lf transmission makes a clicking, grinding orwhirring noise,also replace mainshaft 4th gear, reverse idler gear. and countershaft 4th gear in addition to 1, 2, 3 or 4.lf differential pinion shaft is worn, overhaul differential assembly, and replace ATF strainer, and thoroughlyclean transmission, flush torque converter, cooler and lines.lf bottom of 3rd clutch is swirled and transmission makes gear noise, replace the countershaft and final drivengear.
Be very careful not to damage the torque converter housing when replacing the main ball bearing, you
may also damage the ATF pump when you torque down the main valve body. This will result in ATF pumpseizure if not detected. Use the oroper roors.
Install the main seal flush with the torque converter housing. lf you push it into the torque converterhousing until it bottoms out, it will block the fluid return passage and result in damage.
See flushing procedure, page 14-187 and 188.
lf the large clutch piston O-ring is broken, inspect the piston groove for rough machining.
lf the l-2 shift valve is stuck closed, the transmission will not upshift. lf stuck open, the transmission hasno 1st gear.
lf the znd orifice control valve is stuck. inspect the 2nd and 3rd clutch oacks for wear.
lf the 3-4 orifice control valve is stuck, inspect the 3rd and 4th clutch oacks for wear.
lf the clutch pressure control valve is stuck closed, the transmission will not shift out of 1st gear.
lf the ATF strainer is clogged with particles of steel or aluminum, inspect the ATF pump and differentialpinion shaft. lf both are OK and no cause for the contamination is found, replace the torque converter.
Inspect the frame for collision damage.
14-112
Stall Speed
Test
CAUTION:
. To prev€nt transmission damage, do not t6st stall speed for more than ro sgconds at a time.. Do not shift the levor while raising the engine speed.. Bo sule lo remove the pressure gauge betoro testing stall speed.
'1. Engage the parking brake, and block the front wheels.
2. Connect a tachometer to the engine, and start the engine.
3. Make sure the Ay'C switch is OFF.
4. After the engine has warmed up to normal operating temperature (the radiator fan comes on). shift into E position.
5. Fully depress the brake pedal and accelerator for 6 to g seconds, and note engine speed.
6. Allow two minutes for cooling, then repeat the test in @ and @ positions.
NOTE:
. Stall speed tests should be used for diagnostic purposes only,. Stall speed should be the same in o., E and E positions.
Stall Spsed RPM:
Specification: 2.700 rpm
Service Limit: 2,550 - 2,850 rDm
TROUBLEPROBABLE CAUSE
. Low fluid level or ATF pump outDur. Clogged ATF strainer. Pressure regulator valve sluck closeo. Slipping clutch
. Slippage of 4th ctutch
. Slippage of 2nd clutch
. Slippage of lst clut"tr or. t"t g""io*-*"y "lut"h
Stall rpm high in D., E and E positions
Stall rpm high in El position
Stall rpm high in E posirion
Stall rpm high in E position
Stall rpm low in LDa . El and E positrons. Engine output low. Torque converter one-way clutch slipping
14-116
Fluid Level
Ghecking
NOTE: Keep all foreign particles out of the transmis-
sron.
1.Warm up the engine to normal operating tempera-
ture (the radiator fan comes on)
Park the vehicle on the level ground, then turn off
the engrne.
Remove the dipstick (yellow loop) from the trans-
mission. and wipe it with a clean cloth.
Insert the dipstick into the transmrssron
Remove the dipstick and check the fluid level lt
should be between the upper mark and lower
marks.
UPPER MABKLOWER MARK
lf the level is below the lower mark, pour the recom-
mended fluid into the tiller hole to bring it to the
upper mark. Always use Genuine Honda Premium
Formula Automatic Transmission Fluid (ATF). Using
a non-Honda ATF can affect shift quality
K
L
DIPSTICK IYELLOW LOOPI
7. Insert the dipstick back into the transmission in the
direction shown.
FRONT
Installthe dipstick in the extent
of the direction shown.
14-117
Fluid Level
Changing
NOT€: Keep all foreign particles out of the transmis-sion.
'1.Bring the transmission up to operating temperature(the radiator fan comes on) by driving the vehicle.
Park the vehicle on the level ground, and turn theengine off.
Remove the drain plug. and drain the automatictransmission fluid (ATF).
NOTE: lf a cooler flusher is to be used, see page 14-187 and 14-188.
TRANSMISgION END OOVER
DNAIN PLUG18 x 1.5 mm49 N.m (5.0 kgtm, 36lbf.ftlSEALING WASHERReplace.
Reinstall the drain plug with a new sealing washer,then refill the transmission with the recommended
fluid into the filler hole to the upper mark on thedipstick. Always use Genuine Honda premium
Formula Automatic Transmission Fluid (ATF). Usinga non-Honda ATF can aftect shift quality.
Automatic Transmission Fluid Capacity:
2.7 | |'2.9 US ql,2.a lmp qtl at Ghlnging
5.9 f 16.2 US qt. 5.2 lmp qt) at overhaul
I
14-11A
Pressure Testing
@I While testing, be caroful of th€ rotating front wheels.
. Make sure lifts, iacks, and satoty stands are placod properly (see section 1)'
CAUTION:
. Beforo iesting, be sure the transmission fluid is tilled to tho proper level'
. Warm up tho engine before testing'
1. Raise the vehicle (see section 1).
2. Warm up the engine, then stop the engine and connect a tachometer'
3. Connect the oil pressure gauges to each inspection hole.
TOROUE: 18 N.m (1.8 kgf'm, 13 lbnft)
cAUTloN: connact the oil pressuro gauges securely; be suro not to allow dust and other foreign Parlicles to entel
the inspestion holos'
A/T OIL PRESSURE GAUGESET w/PANEL07t06 - 0020400
A/T LOW PRESSURE GAUGE
SET WPANEL07406 - 0070300
A/T OIL PRESSURE HOSEADAPTER07Mru - PY0120(4 requiJedl
A/T OIL PBESSURE HOSE
2210 mmOTMAJ - PY4{)llA
14 roquircdl
Start the engine, and measure the respective ptessure as follows'
a Line Pressure
. 1st Clutch Pressure
. 2nd,3rd and 4th Clutch Pressure
Install a new washer and the sealing bolt in the inspection hole. and tighten to the specified torque'
TOROUE: l8 N.m (1.8 kgf'm,13lbf'ft)
NOTE: Do not reuse old sealing washers; always replace washers'
(cont'd)
14-119