1995 ACURA TL change wheel

Description

The automatic transmission is a combination of a 3-element torque converter and a dual-shaft electronically controlled

automatic transmission which provides 4 speeds forward and 1 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, 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 drive plate is a ring gear which

meshes with the starter pinion when the engine is being started.

The entire torque converter assembly serves as a flywheel while transmitting power to the transmission mainshaft.

The transmission has two parallel shafts: the mainshaft and the countershaft. The mainshaft is in line with the engine

crankshaft. The mainshaft includes the 1st, 4th and 2nd clutches and gears for 4th, 1st, 2nd and reverse (3rd gear is integral

with the mainshaft). The countershaft includes the 3rd, 1st-hold and reverse clutches, and gears for 3rd, 4th, 1st, 2nd,

reverse and parking. The secondary drive gear is integrated with the countershaft. The gears on the mainshaft are in con-

stant mesh with those on the countershaft. When certain combinations of gears in the transmission are engaged by clutch-

positions.

and
es, power is transmitted from the mainshaft to the countershaft to provide

Electronic Control

The electronic control system consists of a Powertrain Control Module (PCM), sensors, a linear solenoid and four solenoid

valves. Shifting and lock-up are electronically controlled for comfortable driving under all conditions.

The PCM is located below the dashboard, under the front lower panel on the passenger's side.

Hydraulic Control

The lower valve body assembly includes the main valve body, the secondary valve body, the throttle valve body, the lin-

ear solenoid, the shift control solenoid valves and the ATF passage body. They are bolted on the lower part of the trans-

mission housing. The regulator valve body, the ATF pump body, and the accumulator body are bolted to the torque con-

verter housing.

The main valve body on '96 model contains the manual valve, the 1-2 shift valve, the 2-3 shift valve, the 3-4 shift valve, the

4-3 kick-down valve and the Clutch Pressure Control (CPC) valve. The main valve body on '97 model contains the manual

valve, the 1-2 shift valve, the 2-3 shift valve, the 3-4 shift valve, the 4-3 kick-down valve and the main orifice control valve.

The secondary valve body on '96 model contains the 3-4 orifice control valve, the 4-3 shift timing valve, the modulator valve

and the accumulator pistons.The secondary valve body on '97 model contains the 3-4 orifice control valve, the 4-3 shift tim-

ing valve, the line pressure control valve, the modulator valve and the accumulator pistons. The throttle valve body

includes the throttle valve which is bolted onto the secondary valve body. The linear solenoid is joined to the throttle valve

body. The regulator valve body contains the regulator valve, the lock-up shift valve and the cooler relief valve. Fluid from

the regulator passes through the manual valve to the various control valves. The ATF pump body contains the lock-up tim-

ing valve, the lock-up control valve and the relief valve. The torque converter check valve is located in the torque converter

housing under the ATF pump body. The accumulator body contains the accumulator pistons. The reverse accumulator and

the 1st-hold accumulator pistons are assembled in the rear cover.

The 1st, 1st-hold, 2nd and reverse clutches receive fluid from their respective feed pipes, and the 3rd and 4th clutches

receive fluid from the internal hydraulic circuit.

Shift Control Mechanism

Input from various sensors located throughout the vehicle determines which shift control solenoid valve the PCM will acti-

vate. 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 the clutch and its corresponding gear.

er 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 crankshaft. Together with hydraulic control, the PCM optimizes the tim-

ing 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 throttle valve. When lock-up control solenoid valves A and B activate, modulator pressure changes. The lock-

up control solenoid valves A and B are mounted on the torque converter housing, and are controlled by the PCM.

(cont'd)
Lock-up Mechanism

In
position, in 2nd, 3rd, and 4th, and
position in 3rd, pressurized fluid is drained from the back of the torque convert-ProCarManuals.com

Description

The automatic transmission is a combination of a 3-element torque converter and a dual-shaft electronically controlled

automatic transmission which provides 4 speeds forward and 1 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, 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 drive plate is a ring gear which meshes with the starter pinion when the engine is being started.

The entire torque converter assembly serves as a flywheel while transmitting power to the transmission mainshaft.

The transmission has two parallel shafts: the mainshaft and the countershaft. The mainshaft is in line with the engine

crankshaft.

The mainshaft includes the 1st, 2nd and 4th clutches, and gears for 4th, 2nd, 1st and reverse (3rd gear is integral with the

mainshaft, while the reverse gear is integral with 4th gear).

The countershaft includes the 3rd, and 1st-hold clutches, and gears for 3rd, 4th, 1st, 2nd, reverse, and parking. The sec-

ondary drive gear is integrated with the countershaft.

The gears on the mainshaft are in constant mesh with those on the countershaft.

When certain combinations of gears in the transmission are engaged by clutches, power is transmitted from the mainshaft

to the countershaft to provide and positions.

Electronic Control

The electronic control system consists of the Transmission Control Module (TCM), sensors, a linear solenoid and four

solenoid valves. Shifting and lock-up are electronically controlled for comfortable driving under all conditions.

The TCM is located below the dashboard, behind the glove box on the passenger's side.

Hydraulic Control

The lower valve body assembly includes the main valve body, the servo body and the shift control solenoid valves. They

are bolted on the lower part of the transmission housing.

Other valve bodies, the regulator valve body, the ATF pump body, the 2nd accumulator body, and the throttle valve body,

are bolted to the torque converter housing.

The main valve body contains the manual valve, the 1 - 2 shift valve, the 2 - 3 shift valve, the 3 - 4 shift valve, the 4th kick-

down valve, the 2 - 3 orifice control valve, the 3 - 4 orifice control valve, the 4th exhaust valve, the servo control valve,

and the main orifice control valve.

The servo body contains the servo valve, 3rd and 4th accumulator pistons.

The regulator valve body contains the regulator valve, the lock-up shift valve, and the cooler relief valve.

Fluid from the regulator passes through the manual valve to the various control valves.

The throttle valve body includes the throttle valve which is bolted onto the 2nd accumulator body. The 2nd accumulator

piston is assembled in the 2nd accumulator body.

The linear solenoid is joined with the throttle valve body.

The ATF pump body contains the modulator valve, the lock-up control valve, the lock-up timing valve, and the relief valve.

The torque converter check valve is located in the torque converter housing under the ATF pump body.

The 1st and 1st-hold accumulator pistons are assembled in the rear cover.

The clutches receive fluid from their respective feed pipes or internal hydraulic circuit.

Shift Control Mechanism

Input from various sensors located throughout the vehicle determines which shift control solenoid valve the TCM will acti-

vate. 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 in position in 3rd, pressurized fluid is drained from the 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 crankshaft. Together with hydraulic control, the TCM 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 throttle valve. When lock-up control solenoid valves A and B activate, the modulator pressure changes.

The lock-up control solenoid valves A and B are mounted on the torque converter housing, and are controlled by the TCM.ProCarManuals.com

Wheel Alignmen t
Caster
NOTE : Fo r prope r inspection/adjustmen t o f th e whee l
alignment , chec k an d adjus t th e followin g befor e check -
ing th e alignment .
• Chec k tha t th e suspensio n i s no t modified .
• Chec k th e tir e siz e an d tir e pressure .
• Chec k th e runou t o f th e wheel s an d tires .
• Chec k th e suspensio n bal l joints . (Hol d th e whee l wit h
you r hands , the n mov e i t u p an d down , an d righ t an d
lef t t o chec k fo r wobbling. )
Inspection
NOTE: Us e commercially-availabl e computerize d fou r
whee l alignmen t equipmen t t o measur e whee l align -
men t (caster , camber , toe , and/o r turnin g angle) .
Follo w th e equipmen t manufacturer' s instructions .
1 . Chec k th e caste r angle .
Caste r angle : 2°07 ' ± 1 °
2 . I f ou t o f specification , recor d th e caste r reading , the n
adjus t th e caster .
Adjustmen t
NOTE: Caste r angl e ca n b e adjuste d b y increasin g o r
decreasin g th e numbe r o f th e adjustin g shims . Remov e
an d instal l th e radiu s ro d eac h tim e th e caste r angl e i s
adjusted .
1. Rais e th e fron t o f th e vehicle , an d suppor t i t wit h
safet y stand s in th e prope r location s (se e sectio n 1 ).
2 . Remov e th e self-lockin g nu t o n th e en d o f th e radiu s
rod.
3. Remov e th e flang e bolt s a t th e radiu s ro d o n th e lowe r
arm , the n remov e th e radiu s ro d (se e pag e 18-19 ).
4 . Adjus t th e caste r angl e b y increasin g o r decreasin g
the adjustin g shims .
NOTE:
• D o no t us e mor e tha n tw o adjustin g shims .
• On e adjustin g shi m change s th e caste r angl e b y
35 ' an d th e caste r angl e ca n b e adjuste d b y 1°10 '
maximum .
• On e adjustin g shi m is 3. 2 m m (0.1 3 in ) i n thick -
ness.
ADJUSTIN G SHI M
RADIU S RO D
SELF-LOCKIN G NU T
12 x 1.2 5 mm54 N- m (5. 5 kgf-m , 4 0 Ibf-ft )Replace .
5. Afte r th e adjustment , instal l th e radiu s ro d ont o th e
lowe r arm , the n tighte n th e flang e bolt s (se e pag e
18-19 ).
6 . Tighte n th e ne w self-lockin g nu t t o specifie d torque .
ProCarManuals.com

Anti-lock Brake System (ABS)

Operation (cont'd)

Proportioning Control Valve Function:

The modulators for the rear brakes serve as proportioning

control valves to prevent the rear wheels from locking if

the ABS malfunctions or when the ABS is not activated.

When this function is not provided, the hydraulic pressure

from the master cylinder and the hydraulic pressure to

the rear brake system are equal.

If the fluid pressure is transmitted to the rear brakes at

the same rate as the front brakes, the rear wheels will

lock first because the rear axle load becomes lighter

when the brakes are applied.

To prevent the rear wheels from locking, the proportion-

ing control valve function changes the distribution rate

of the fluid pressure to the rear wheels when the pres-

sure in the rear brake system exceeds the given value of

the fluid pressure from the master cylinder. The fluid

pressure point where the distribution rate changes is

called the turning point.
FLUID PRESSURE WITHOUT PCV

FLUID PRESSURE WITH PCV

TURNING POINT

MASTER CYLINDER FLUID PRESSURE

The cut valve seat in the rear brake system has a shoulder between sections A and B. Section A, where pressure from the

master cylinder is applied, has a smaller diameter than section B, where pressure from the rear brake caliper is applied.

This design provides the proportioning control valve function as follows.

1. When the fluid pressure from the master cylinder is below the turning point, the cut valve seat is pushed by the

spring force and the cut valve is open. Therefore, the fluid pressure from the master cylinder is transmitted to the

rear brake caliper side. Under these conditions, fluid pressure from the master cylinder is equal to the pressure to the

rear brake caliper, but because of the diameter difference between sections A and B, the force on the cut valve over-

comes the spring force, moving the cut valve seat toward the cut valve slowly.

2. When the fluid pressure to the rear brake caliper reaches the turning point, the cut valve is closed by the cut valve

seat, blocking the fluid passage between the master cylinder side and rear wheel cylinder side.

3. When the fluid from the master cylinder exceeds the turning point, the fluid pressure from the master cylinder rises,

while the pressure to the rear brake caliper remains at the turning point value. As a result, the cut valve seat moves

away from the cut valve and the cut valve opens. The passage between the master cylinder and caliper opens

momentarily, but it is blocked again because the fluid pressure to the brake caliper rises, and the cut valve seat

moves to close the cut valve. As described above, when the pressure in the master cylinder is above the turning

point, the cut valve seat reduces the pressure in the rear brake caliper to the prescribed amount by repeating this pro-

cess.

From MASTER CYLINDER

To REAR BRAKE CALIPER

SPRING FORCE

SECTION WHERE PRESSURE FROM REAR CALIPER IS APPLIED.

SECTION WHERE PRESSURE FROM MASTER CYLINDER IS APPLIED.
CUT VALVE SEATProCarManuals.com

Wheel Speed and Modulator Control

When the wheel speed drops sharply below the vehicle speed, the inlet valve closes to retain the caliper fluid pressure.

When the wheel speed drops further, the outlet valve opens momentarily to reduce the caliper fluid pressure. The pump

motor starts at this time.

As the wheel speed is restored, the inlet valve opens momentarily to increase the caliper fluid pressure.

Wheel Sensor

The wheel sensors are the magnetic contactless type.

As the gear pulser teeth rotate past the wheel sensor's magnetic coil, AC current is generated. The AC frequency changes

in accordance with the wheel speed. The ABS control unit detects the wheel sensor signal frequency and thereby detects

the wheel speed.

There are four wheel sensors, one for each wheel.

The gear pulser has 50 teeth.

GEAR PULSER

WHEEL SENSORProCarManuals.com