ACURA NSX 1991 Service Repair Manual

Illustrated Inde x
CAUTION : D o no t tr y to disassembl e th e powe r steerin g gearbox . I f th e gearbo x is faulty , replac e it a s a n assembly .
Corrosion resistan t bolt/nu t10 x 97 m mFLANG E BOL T
GEARBO X ASSEMBL Y STEERIN
G
GEARBO X BRACKE T
CUSHION BChec k fo r damage .
10 x 84 m mFLANG E BOL T60 N- m(6.0 kg-m , 4 3 Ib-ft )
10 x 97 m mFLANG E BOL T60 N- m(6.0 kg-m , 4 3 Ib-ft )
MOUN T BAS E
10 m m FLANG E NU T60 N- m(6.0 kg-m . 4 3 Ib-ft )
FLANG E BOL T10 N- m(1.0 kg-m , 7 Ib-ft )
GROUN D CABL E
STO P WASHE R
LOC K WASHE R
Replace.RACK EN D
TIE-ROD EN D
STEERIN
G GROMME T
Chec k fo r damage .
WIR E HARNES S STA Y
1 0 m m FLANG E NU T
60 N- m(6.0 kg-m , 4 3 Ib-ft )
FLANG E BOL T10 N- m(1.0 kg-m , 7 Ib-ft )
MOUN T COLLE R
MOUNT BUSHIN GCheck fo r damage .
FLANGE BOL T
10 N- m(1.0 kg-m , 7 Ib-ft )
TERMINA L
GUAR D
COTTE R PI N
Replace .
CASTL
E NU T
44 N- m(4.4 kg-m , 3 2 Ib-ft )
TUB E CLAM P
BOOT
Replace .
SE T RIN G
STEERIN
G GREAS E
(Honda P/ N 08733-B070E )Coat th e insid e o f th e boot .
SILICON E GREAS E
Coa t th e slidin g surfac e
o f th e rac k end .
TIE-RO DLOCKNU T44 N.m(4.4 kg-m , 3 2 Ib-ft )
5
5 N- m (5. 5 kg-m , 4 0 Ib-ft )
BOO T
Chec k fo r damage .
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Steering Gearbo x
Inspectio n
1. Carefull y clam p th e gearbo x i n a vis e wit h sof t jaws .
2 . Remov e th e boo t bands .
BOOT BAN DReplace .
3. Pul l th e boot s awa y fro m th e end s o f th e gearbox ,
the n unben d th e tie-ro d loc k washers .
4 . Hol d th e rac k wit h a wrench , an d unscre w th e tie -
rod s wit h anothe r wrench .
LOCK WASHE RReplace.
• Preloa d inspection :
Slide th e steerin g rac k in th e cylinde r unti l th e en d o f
th e rac k project s 6 0 m m (2. 4 in ) fro m th e cylinde r
end . Inspectio n is mad e nea r thi s rac k position .
CYLINDE R
RACK
Instal l th e specia l too l o n th e pinio n shaf t an d chec k
th e preloa d wit h a sprin g scale .
I f th e preloa d i s ou t o f th e specification , adjus t th e
rac k guide .
Preloa d 3 0 N (3 kg , 6. 6 Ibs ) maximu m
STEERIN G INSPECTIO N AR M0797 4 - SD9000 0
Rac k guid e scre w adjustment :
— Loose n th e rac k guid e scre w locknut .
— Tighten , loose n an d retighte n th e rac k guid e scre w
tw o time s t o 4 N- m (0. 4 kg-m , 2. 9 Ib-ft) , the n bac k
it of f 20 °
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Retighten th e locknu t whil e holdin g th e rac k
guid e scre w wit h a wrench .
LOCKNU T25 N- m (2. 5 kg-m , 1 8 Ib-ft )
LOCKNU T WRENCH , 4 0 m m0791 6 - SA5000 1 Tie-ro
d installation :
5 . Scre w eac h rac k en d int o th e rac k whil e holdin g th e
loc k washe r s o it s tab s ar e i n th e slot s i n th e rac k
end.
NOTE : Instal l th e stoppe r washe r wit h th e cham -
fere d sid e facin g out .
LOC K WASHE RReplace.
TAB
RAC K EN D STOPPE R WASHER
6. Tighte n th e rac k en d securely , the n ben d th e loc k
washe r bac k agains t th e fla t o n th e flang e a s shown .
NOTE : Coa t th e stoppe r washe r wit h greas e suffi -
ciently .
RACK EN D55 N- m(5.5 kg-m , 4 0 Ib-ft )
SLOT
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Steering Gearbo x
Inspectio n
7. Instal l th e boot s o n th e rac k en d wit h th e tub e clamps .
NOTE:
• Coa t th e rac k en d an d insid e o f th e boo t wit h th e
grease .
• Befor e installin g th e boot , b e sur e tha t th e pres -
sur e insid e o f th e boo t i s th e atmospheri c pres -
sure.
• Instal l th e boo t ban d wit h th e rac k i n th e straigh t
ahea d conditio n (righ t an d lef t tie-rod s ar e equa l
i n length) .
BOOT
TUBE CLAM P
STEERIN G GREAS E(Honda P/ N 08733-B070E )Coat th e insid e o f th e boot .
SILICON E GREAS ECoat th e slidin g surfac eof th e rac k end .
8. Instal l th e ne w boo t band s o n th e boot , an d ben d
bot h set s o f lockin g tabs . Lightl y ta p o n th e double d
portion s t o reduc e thei r height .
NOTE : Afte r assembling , slid e th e rac k righ t an d
lef t t o b e certai n tha t th e boot s ar e no t deforme d o r
twisted .
LOCKIN G TAB S
BOOT BAN DReplace .
9. I f th e tie-ro d end s wer e removed , instal l th e tie-rod s
o n th e righ t an d lef t rac k end s an d scre w the m in
unti l th e threade d sectio n is 1 1 m m (0. 4 in ) i n length .
11 m m (0. 4 in)
LOCKNU THand tighten .
TIE-RO D EN D
10. Instal l th e gearbo x an d th e fron t crossbea m in th e
revers e orde r remova l (se e pag e 17-57 ).
11 . Chec k th e whee l alignmen t an d adjus t i f necessar y
(se e sectio n 18 ).
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Ball Join t Boo t
Replacemen t
1. Remov e th e se t rin g an d th e boot .
CAUTION : D o no t contaminat e th e boo t installa -
tio n sectio n wit h grease .
2 . Pac k th e interio r o f th e boo t an d li p wit h grease .
BOOT INSTALLATIO N SECTIO N
3. Wip e th e greas e of f th e slidin g surfac e of the bal l
pin , the n pac k th e lowe r are a wit h fres h grease .
CAUTION :
• Kee p greas e of f th e boo t installatio n sectio n an d
th e tapere d sectio n o f th e bal l pin .
• D o no t allo w dust , dirt , o r othe r foreig n material s
t o ente r th e boot .
BALL PI N TAPERE DSECTION
BOO T INSTALLATIO N
SECTIO N
4. Instal l th e boo t i n th e groov e o f th e boo t installatio n
sectio n securely , the n blee d air . 5
. Inser t th e specia l too l int o th e thread s i n th e bal l pin ,
and alig n th e en d o f th e too l wit h th e groov e in th e
boot . Slid e th e se t rin g ove r th e too l an d int o position .
SET RIN G
CAUTION : Afte r installin g th e boot , chec k th e bal l
pi n tapere d sectio n fo r grease . Wip e it i f necessary .
LIP
BAL L JOIN T BOO T CLI P GUID E07MAG - SL0010 0
Adjus t th e dept h b y
turnin g th e tool .
BOO T
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EPS Contro l Uni t
Replacemen t
SRS component s ar e locate d i n thi s area . Revie w th e
SR S componen t locations , precautions , an d procedure s
i n th e SR S sectio n 24 befor e performin g repair s o r ser -
vice .
1 . Remov e th e dashboar d lowe r cover .
DASHBOAR D LOWE R COVE R
2. Tur n u p th e floo r mat , an d remov e th e speake r cove r
an d speaker .
SPEAKE R COVE R
SPEAKE R
3. Disconnec t th e connector s fro m th e EP S contro l
unit , the n remov e it .
10 N- m (1. 0 kg-m , 7 Ib-ft )
3P CONNECTOR SEPS CONTRO L UNI T
18P CONNECTO R
10 N- m (1. 0 kg-m , 7 Ib-ft )
4. Installatio n is th e revers e o f remova l procedure .
NOTE : Afte r installation , star t th e engin e an d mak e
sur e tha t th e EP S indicato r ligh t goe s off .
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Special Tool s
18-33, 18-34
18-18, 18-34
18-18, 18-3318-26, 18-39
18-21, 18-22,
18-24, 18-37
18-21, 18-3618-26 18-18 , 18-3418-39
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Component Locations
Index
Front Suspension:FRONT DAMPERRemoval, page 18-27Disassembly/Inspection, page 18-27Reassembly, page 18-29Installation, page 18-29Disposal . . . . . . . . . 18-44
FRONT SUSPENSION ASSEMBLY• Knuckle/Control Arms/ Compliance PivotRemoval, page 18-21• Illustrated Index, page 18-20• Ball Joint Boot Replacement,page 18-26
FRONT HUBReplacement, page 18-15Rear Suspension:
REAR DAMPERRemoval, page 18-40Disassembly/Inspection, page 18-42Reassembly, page 18-44Installation. page 18-44Disposal . . . . . . . . . 18-44
REAR HUBReplacemen t, page 18-31
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System Description

Suspension Composition

Outline

Double wishbone independent suspension has been selected for each of the four wheels. This eliminates damper friction

along the steering axis, and permits suspension geometry that takes full advantage of the performance potential of the

wide, low aspect ratio tires. The double wishbone design also allows the use of aerodynamically-efficient and

aesthetically pleasing low fender lines.

The knuckles and the suspension arms are manufactured from lightweight, high-strength aluminum alloys. This gives a

notable reduction in unsprung weight which results in increased traction and improved ride. It also allows the individual

suspension components to be designed in detail for maximum strength and rigidity.

FRONT

UPPER

CONTROL

ARM
KNUCKLE

STABILIZER
REAR

UPPER

CONTROL

ARM
STABILIZER

KNUCKLE

LOWER CONTROL ARM

LOWER CONTROL ARM

To further increase suspension link rigidity, and to obtain optimum knuckle geometry, the knuckles and ball joints are

contained within the wheel profile. At each corner of the car, the individual suspension system is attached to the alumi-

num stressed skin chassis by a cast aluminum sub-frame. This design further reduces overall weight, and ensures that

suspension loads are fed into the chassis at the most efficient points, and in the most efficient directions.

A large front caster angle combined with small trail distance improves straight-line stability and response without caus-

ing heavy steering effort.

FRONT
REAR

SUB-FRAME

SUB-FRAMEProCarManuals.com

(Front Compliance Mechanism)

To avoid the usual compromise between ride quality and handling characteristics, a pivot-type "compliance mechanism"

has been designed as an integral part of the front suspension. When one of the front wheels is subjected to a rearward

movement by an uneven road surface or by heavy braking, the load produced has two separate effects. As with any

suspension system, the load acts in the vertical direction to compress the suspension spring and reduce the ride height.

On the NSX/NSX-T the load also acts through both the upper and lower control arms to twist the compliance pivot. This

allows the wheel to move rearward by a controlled amount, thus absorbing energy. The result is an outstanding ride

quality with only minimal changes to track width and wheel geometry. In cornering, the compliance pivot does not come

into play, and the lateral suspension stiffness required for maximum roadholding and optimum control response is main-

tained.

COMPLIANCE

PIVOT

TOP VIEW

(Rear Toe Control Arm)

Many conventional passenger-car independent rear suspension systems are subject to undesirable changes in toe-in

angle with wheel movement. This results in instability both in cornering and in acceleration. In the NSX/NSX-T, the de-

sign and pivot locations of the rear toe control arm produce a slight controlled increase in toe-in during bump travel. As

a result, the NSX/NSX-T is extremely stable under heavy cornering loads and over bumpy road surfaces.

TOP VIEW

TOE CONTROL ARM
COMPLIANCE

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