1997 ACURA NSX transmission

Bearing Preload

Adjustment

If any of the items listed below are replaced, the bearing

preload must be adjusted.

• TRANSMISSION HOUSING

• CLUTCH HOUSING

• DIFFERENTIAL

• TAPERED ROLLER BEARING and OUTER RACE

• 75 mm THRUST SHIM

• 90 mm WASHER

• OIL GUIDE RING

1 . Remove the bearing outer race and 75 mm thrust

shim from the transmission housing by prying up

on the bearing outer race or by heating the housing

to about 212°F (100°C).

CAUTION: Do not reuse the thrust shim if the

outer race was pried out.

NOTE:

• If the outer race was removed by heating the

case, let the transmission cool to room tempera-

ture before adjusting the bearing preload.

• Do not heat the transmission housing in excess

of 212°F (100°C).

• Replace the bearing with a new one whenever

the outer race is replaced.

• Repeat on the clutch side.

BEARING OUTER

RACE
75 mm THRUST SHIM

Replace.

TRANSMISSION

HOUSINGProCarManuals.com

1. Install the clutch disc, clutch plate, central gear, and

carrier assembly. Lubricate the clutch disc surface

with transmission fluid.

CARRIER ASSEMBLY

CENTRAL GEAR

CLUTCH PLATE

CLUTCH DISC

DIFFERENTIAL

HOUSING

COVER

2. Install the final driven gear. Align the mark on the

differential housing cover with the mark on the final

driven gear.

FINAL

DRIVEN

GEAR

MARK

MARK
3. Install the 102 mm washer, clutch discs, clutch

plates, and 112 mm thrust shim. Lubricate the

clutch discs with transmission fluid. Position the

112 mm thrust shim with the thickness size mark

facing away from the clutch discs.

Thickness Size

Mark

CLUTCH PLATES
112 mm THRUST

SHIM

CLUTCH DISCS

102 mm WASHER

4. Install the 60 mm washer, spring plate, and stop

plate.

STOP PLATE

SPRING PLATE

60 mm WASHER

DIFFERENTIAL

HOUSING
Differential

ReassemblyProCarManuals.com

Oil Seal

Removal

1. Remove the differential assembly.

2. Remove the oil seal from the transmission housing.

OIL SEAL

Replace.
TRANSMISSION

HOUSING

3. Remove the oil seal from the torque converter

housing.

OIL SEAL

Replace.
TORQUE CONVERTER

HOUSINGProCarManuals.com

Bearing Preload

Adjustment

NOTE: If any of the items listed below are replaced, the

bearing preload must be adjusted.

TRANSMISSION HOUSING

TORQUE CONVERTER HOUSING

DIFFERENTIAL

TAPERED ROLLER BEARING and OUTER RACE

75 mm THRUST SHIM

90 mm WASHER

OIL GUIDE RING

1. Remove the bearing outer race and 75 mm thrust

shim from the transmission housing by prying up

on the bearing outer race or by heating the housing

to about 212°F (100°C).

CAUTION: Do not reuse the thrust shim if the

outer race was pried out.

NOTE:

• If the outer race was removed by heating the

case, let the transmission cool to room tempera-

ture before adjusting the bearing preload.

• Do not heat the transmission housing in excess

of 212°F (100°C).

• Replace the bearing with a new one whenever

the outer race is replaced.

• Repeat on the torque converter side.

BEARING OUTER

RACE

TRANSMISSION

HOUSING

75 mm THRUST SHIM

Replace.ProCarManuals.com

Steering Gearbox

Motor and Power Assist Mechanism

A motor is housed inside the gearbox housing. It consists of a yoke with a permanent magnet fixed in it, a rotor with a

field coil, and brushes which pass electricity to rotor commutators. The motor is on the rack shaft of the steering gearbox.

The drive current from the control unit flows through the power relay and fail-safe relay to the brushes of the motor.

The drive current flows to rotor commutators through brushes, exciting the field coil of the rotor and rotates the rotor with

the magnetic action of the permanent magnet inside the yoke. The rotor rotates in the opposite direction when the direc-

tion of drive current is reversed.

The rotation torque of the motor is transmitted to the ball screw throught the helical gear. The rotation torque on the ball

screw is converted into assist thrust in the direction of steering rack by the recirculating ball screw. The mechanical advan-

tage of the recirculating ball screw, compaired to a conventional rack and pinion, acts to reduce the steering force to the

steering rack through the joint, to lessen the steering effort required at the steering wheel.

Recirculating Ball Screw

The recirculating ball screw is constructed so that steel balls roll between the screw shaft and the nut, and those coming

out of the screw face enter the screw groove again through a tube for recirculation. The rotation torque on the shaft is

converted into thrust in an axial direction as the slope of the screw shaft presses against the nut through the steel balls.

Since the torque conversion is made in this method through the screw shaft and the steel balls, the friction is small, high

transmission efficiency is obtained for both the forward and backward directions, and the steering feels identical to the

ordinary manual steering.

Furthermore, since the force from the backward direction (force pressing the steering rack) is converted into the rotation

torque of the screw shaft, instantaneous kick-back from the road surface will rapidly rotate the motor. In such a rapid rota-

tion, the inertia of the motor increases, which acts to reduce the kick-back. Any great kick-back will be transmitted from the

steering rack to the torque sensor on the pinion, which acts to twist the pinion shaft in the same direction as the input

direction of kick-back. As a result, the motor operates the kick-back to reduce assist force.ProCarManuals.com

Tests
Brake Booster

Functional Test

1. With the engine stopped, depress the brake pedal

several times to deplete the vacuum reservoir, then

depress the pedal hard and hold it for 15 seconds. If

the pedal sinks, either the master cylinder is

bypassing internally, or the brake system (master

cylinder, lines, modulator, proportioning valve, or

calipers) is leaking.

2. Start the engine with the pedal depressed. If the

pedal sinks slightly, the vacuum booster is operat-

ing normally, if the pedal height does not vary, the

booster or check valve is faulty.

3. With the engine running, depress the brake pedal

lightly. Apply just enough pressure to hold back

automatic transmission creep. If the brake pedal

sinks more than 10 mm (3/8 in.) in three minutes,

the master cylinder is faulty. A slight change in

pedal height when the A/C compressor cycles on

and off if normal. (The A/C compressor load

changes the vacuum available to the booster.)

Leak Test

1. Depress the brake pedal with the engine running,

then stop the engine. If the pedal height does not

vary while depressed for 30 seconds, the vacuum

booster is OK. If the pedal rises, the booster is

faulty.

2. With the engine stopped, depress the brake pedal

several times using normal pressure. When the

pedal is first depressed, it should be low. On con-

secutive applications, the pedal height should grad-

ually rise. If the pedal position does not vary, check

the booster check valve.
Booster Check Valve Test

1. Disconnect the brake booster vacuum hose at the

booster or at the booster side of the valve.

2. Start the engine and let it idle. There should be vac-

uum. If no vacuum is available, the check valve is

not working properly. Replace the check valve and

retest.ProCarManuals.com

Steering angl e senso r syste m chec k
1 . Star t th e engine .
2 . Pus h th e TC S switc h thre e time s withi n thre e seconds .
NOTE : Alway s maintai n th e sam e numbe r o f rota -
tions .
3 . Tur n th e steerin g whee l slowl y fro m lef t t o righ t mor e
tha n 1. 5 turns .
NOTE :
• Star t checkin g afte r th e steerin g whee l move s a t
leas t 1. 5 turn s fro m righ t t o left .
• Tur n th e steerin g whee l slowly , n o faste r tha n
on e tur n in fou r seconds .
4 . Pus h th e TC S switc h twic e withi n thre e seconds .
NOTE : Alway s maintai n th e sam e numbe r o f rota -
tions .
5 . Retur n th e steerin g whee l t o th e lef t sid e slowly , an d
chec k th e numbe r o f time s th e TC S indicato r ligh t
flashe s afte r th e whee l ha s move d approximatel y
on e turn .
NOTE :
• Star t th e chec k fro m th e beginnin g whe n th e steer -
in g whee l move s a t leas t on e tur n fro m lef t t o
right .
• Tur n th e steerin g whee l slowly , n o faste r tha n on e
tur n in fou r seconds .
Standar d numbe r o f time s th e TC S indicato r ligh t
flashes :
Manual Transmission : 5 time s
Automati c Transmission : 2 time s
6 . I f ther e is a n abnormality , chec k th e troubleshootin g
flowchar t (se e pag e 19-114 ). Selectio
n o f th e adjustin g shim s fo r th e steerin g angl e
senso r ai r ga p adjustmen t
NOTE:
• Th e adjustmen t o f th e ai r ga p betwee n th e steerin g
shaf t an d th e steerin g angl e senso r shoul d b e carrie d
ou t i n orde r t o obtai n adequat e senso r output .
• Th e adjustin g shi m referenc e numbe r i s stampe d o n
th e steerin g column . Selec t th e adjustin g shim s tha t
matc h th e referenc e numbe r usin g th e tabl e below .
Referenc e Numbe r Location s
Selectio n o f Th e Adjustin g Shi m
Adjustin g Shi m
ProCarManuals.com

Relay and Control Unit Locations

Rear Bulkhead

PGM-FI MAIN RELAY
THROTTLE VALVE CONTROL

MOTOR RELAY

Wire colors: BLK,

YEL/BLK, GRN/RED,

and WHT/BLU

DASH LIGHTS

BRIGHTNESS

CONTROL UNIT
TRANSMISSION CONTROL

MODULE (TCM) (A/T)

PULSE UNIT (M/T)

ABS INDICATOR LIGHT

RELAY

Wire colors: BLU/WHT,

BLK, YEL/BLK, BLU/WHT
TCS CONTROL UNIT

FAN CONTROL

UNIT

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