1991 ACURA NSX Service Repair Manual

Mainshaft Assembly

Disassembly

CAUTION: Remove the synchro hubs using a press and

steel blocks as shown. Use of a jaw-type puller can

damage the gear teeth.

2. Support 5th gear on steel blocks as shown, and

press the shaft out of the 5th synchro hub.

ATTACHMENT
PRESS

5TH SYNCHRO HUB

5TH GEAR

3. In the same manner as above, support the 3rd gear

on steel blocks, and press the shaft out of the

3rd/4th synchro hub.

PRESS

ATTACHMENT

3RD/4TH SYNCHRO HUB

3RD GEARProCarManuals.com

Mainshaft Assembly
Inspectio n
1. Inspec t th e gea r surfac e an d bearin g surfac e fo r
wea r an d damage , the n measur e th e mainshaf t a t
point s A , B , an d C .
Standard :
A (Bal l bearin g surface) : 32.002—32.01 8 m m
(1.2599-1.260 5 in )
B (Needl e bearin g surface) : 42.984—43.00 0 m m
(1.6923-1.692 9 in )
C (Bal l bearin g surface) : 30.984-31.00 0 mm
(1.2198-1.220 5 in )
Servic e limit :
A: 31.95 0 m m (1.257 9 in )
B: 42.93 0 m m (1.690 2 in )
C: 30.93 0 m m (1.217 7 in )
Inspec t oi l passage s fo r clogging .
Inspect fo r wea r an d damage .
If an y par t o f th e mainshaf t i s les s tha n th e servic e
limit, replac e it wit h a ne w one .
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2. Inspect for runout.

Standard: 0.02 mm (0.001 in) max.

Service Limit: 0.05 mm (0.002 in)

NOTE: Support the mainshaft at both ends as

shown.

Rotate two complete revolutions.

If the runout exceeds the service limit, replace the

mainshaft with a new one.ProCarManuals.com

Countershaft Assembl y
Index
NOTE : Th e 3rd , 4t h an d 5t h gear s ar e installe d wit h a press .
Prior t o reassembling , clea n al l th e part s i n solvent , dr y them , an d appl y lubrican t t o an y contac t surfaces .
The 3rd , 4t h an d 5t h gear s shoul d b e installe d withou t lubricatio n usin g a press .
SYNCHR O SPRIN G
SYNCHR O RIN G
Inspection ,page 13-3 5
1S T GEA R
54.5 x 60. 5 x 3 3 m mNEEDL E BEARIN GInspect fo r wea r an d operatio n
THRUST WASHE RSelection, pag e 13-3 0
REVERS E GEA R
COUNTERSHAF TInspection, pag e 13-3 2
SPRIN G WASHE R
BAL L BEARIN G
NEEDL E BEARIN G
5T H GEA R
4TH GEA R
3RD GEA R
2N D GEA R
INNE R SYNCHR O RIN G
SYNCHR O CON E
OUTE R SYNCHR O RIN G
Inspection , pag e 13-3 5
SYNCHR O SPRIN G
52 x 5 7 x 33 m mNEEDL E BEARIN GInspect fo r wea r an d operation .
SPACER COLLA R
Selection , pag e 13-3 0
1ST/2N D SYNCHR O SLEEV E
Inspection , pag e 13-3 6
1ST/2N D SYNCHR O HU B
LOCKNU
T Replace .
155 0 15 5 N- m15. 5 0 15. 5 kg-m ,112 0 11 2 Ib-f t
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Countershaft Assembly
Clearance Inspectio n
1. Measur e th e clearanc e betwee n 2n d an d 3r d gear .
Standard :
0.04-0.10 mm (0.002-0.00 4 in)
3R D GEA R
2ND GEA R
2. I f th e clearanc e exceed s th e standard , selec t th e
appropriat e space r colla r fo r th e correc t clearanc e
fro m th e char t below .
SPACE R COLLA R
3. Measur e th e clearanc e betwee n 1s t an d revers e
gear .
Standard :
0.04-0.10 mm (0.002-0.00 4 in)
1S T GEA R
REVERS EGEAR
4. I f th e clearanc e exceed s th e standard , selec t th e
appropriat e thrus t washe r fo r th e correc t clearanc e
fro m th e char t below .
THRUS T WASHE R
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Disassembly

1. Securely clamp the countershaft assembly in a

bench vise with wood blocks.

2. Raise the locknut tab from the groove of the

countershaft, and remove the locknut and the spring

washer.

NOTE: The locknut has left-hand threads.

WOOD BLOCKS

3. Remove the ball bearing using a bearing puller as

shown.

BEARING PULLER

(Commercially

available)

BALL BEARING

BEARING

SEPARATOR,

0-4 1/2 in.

(Commercially

available)
4. Remove the bearing outer race from the needle

bearing, then remove the needle bearing using a

bearing puller as shown.

BEARING PULLER

(Commercially

available)

NEEDLE BEARING

BEARING

SEPARATOR,

0-4 1/2 in.

(Commercially

available)

CAUTION: Remove the gears using a press and steel

blocks as shown. Use of a jaw-type puller can damage

the gear teeth.

5. Support 4th gear on steel blocks as shown, and

press the shaft out of 5th and 4th gears.

5TH GEAR

4TH GEAR
PRESS

ATTACHMENT
BENCH

VISE
SPRING

WASHER
TAB
CHISELProCarManuals.com

Countershaft Assembl y
Disassembl y
6. Suppor t 2n d gea r o n stee l block s a s shown , an d
pres s th e shaf t ou t o f 3r d an d 2n d gears .
PRESS
ATTACHMEN T
3RD GEA R
2N D GEA R
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Countershaft Assembl y
Inspection
1. Inspec t th e gea r surface s an d bearin g surface s fo r
wea r an d damage , the n measur e th e countershaf t
at point s A an d B .
Standard :
A (Needle bearin g surface) : 43.974-43.99 0 mm
(1.7313-1.731 9 in )
B (Bal l bearin g surface) : 33.984—34.00 0 m m
(1.3380-1.338 6 in)
Servic e Limit :
A: 43.92 0 m m (1.729 1 in )
B: 33.93 0 m m (1.335 8 in )
NOTE : Inspec t oi l passage s fo r clogging .
Inspec t fo r wea r an d damage .
I f an y par t o f th e countershaf t i s les s tha n th e ser -
vice limit , replac e it wit h a ne w one .
2. Inspec t fo r runout .
Standard : 0.0 2 m m (0.00 1 in ) max .
Servic e Limit : 0.0 5 m m (0.00 2 in )
NOTE : Suppor t th e countershaf t a t bot h end s a s
shown .
Rotate tw o complet e revolutions .
If th e runou t exceed s th e servic e limit , replac e th e
countershaf t wit h a ne w one .
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