1991 ACURA NSX service

Mid Plate Guide
Replacement (cont'd)

5. Install the new mid plate guide with the screw
installed.

MII D PLATE GUIDE
SCREW
MI D PLATE

6. Install the washer, spring and guide collar, then
remove the screw.

GUIDE COLLAR

SCREW SPRI
NG

WASHER
MID PLATE GUIDE

Install as shown.

7. Initialize the mid plate guides after installing the
clutch assembly (see page 12-14)

assembly Flywheel, Flywheel Bearing
Inspection
NOTE: If replacement is required, always replace the

pressure plate, mid plate, and flywheel as a set.
1. Inspect the ring gear teeth for wear and damage.
2. Inspect the clutch disc mating surface on the
flywheel for wear, cracks, and burning.

3. Measure the flywheel runout using a dial indicator through at least two full turns. Push against the
flywheel esch time you turn it to take up the
crankshaft thrust washer clearance.

NOTE: The runout can be measured with engine

installed.

Standard (New): 0.05 mm (0.002 in) max.

Service Limit: 0.15 mm (0.006 in)

If the runout exceeds the service limit, replace the
flywheel.

RING

GEAR

FLYWHEEL

4. Turn the inner race of the ball bearing with your
finger. The bearing should turn smoothly and quiet-

ly. Check that the bearing outer race fits tightly in
the flywheel. Replace the bearing if the race does

not turn smoothly, quietly, or fit tightly in the

flywheel.

BALL
BEARING

FLYWHEELProCarManuals.com

Reverse Shift Arm, Reverse Shift Fork

Clearance Inspection

1. Measure the clearance between the reverse shift

arm and the 5th/reverse shift piece.

Standard:
0.05-0.30
mm

(0.002-0.012 in)

Service Limit: 0.5 mm (0.020 in)

REVERSE SHIFT ARM

5TH/REVERSE

SHIFT PIECE

2. If the
clearance exceeds
the
service
limit,
measure

the width of the groove in the reverse shift arm.

Standard:
7.05-7.20
mm
(0.278-0.283
in)

REVERSE SHIFT ARM

If the width of the groove exceeds the standard,

replace the reverse shift arm with a new one.

If the width of the groove is within the standard,

replace the 5th/reverse shift piece with a new one.
3. Measure the clearance between the reverse shift

arm and reverse shift fork.

Standard:
0.05-0.35
mm

(0.002-0.014 in)

Service Limit: 0.5 mm (0.020 in)

REVERSE SHIFT ARM

REVERSE SHIFT FORK

4. If the
clearance exceeds
the
service
limit,
measure

the width of the reverse shift arm.

Standard:
12.8-13.0
mm
(0.504-0.512
in)

REVERSE SHIFT ARM

If the width is less than the standard, replace the

reverse shift arm with a new one.

If the width is within the standard, replace the

reverse shift fork with a new one.ProCarManuals.com

Reverse Shift Arm,

Reverse Shift Fork

Clearance Inspection

5. Measure the clearance between the reverse shift

fork and reverse synchro sleeve.

Standard: 0.45—0.65 mm

(0.018-0.026
in)

Service Limit: 1.0 mm (0.039 in)

REVERSE SYNCHRO SLEEVE
REVERSE SHIFT FORK

6. If the clearance exceeds the service limit, measure

the thickness of the shift fork fingers.

Standard:
6.4-6.5
mm
(0.252-0.256
in)

SHIFT FORK

If the thickness is less than the standard, replace

the reverse shift fork with a new one.

If the thickness is within the standard, replace the

reverse synchro sleeve with a new one.

NOTE: The synchro sleeve and synchro hub

should be replaced as a set.ProCarManuals.com

Change Holder Assembly, Shift Fork

Clearance Inspection

1. Measure the clearance between the shift piece and

shift arm.

Standard: 0.05—0.25 mm

(0.002-0.010
in)

Service Limit: 0.5 mm (0.020 in)

SHIFT ARM
SHIFT PIECE

2. If the clearance exceeds the service limit, measure

the width of the shift arm.

Standard:
12.9-13.0
mm
(0.508-0.512
in)

SHIFT ARM

If the width of the shift arm is less than the stan-

dard, replace the shift arm with a new one.

If the width of the shift arm is within the standard,

replace the shift piece with a new one.
3. Measure the clearance between the interlock and

select arm.

Standard:
0.03-0.15
mm
(0.001
-
0.006
in)

INTERLOCK

SELECT ARM

4. If the clearance exceeds the standard, measure the

width of the interlock finger.

Standard: 11.95 - 12.00 mm

(0.470-0.472 in)

INTERLOCK

If the width of the interlock is less than the stan-

dard, replace the interlock with a new one.

If the width of the interlock is within the standard,

replace the select arm with a new one.ProCarManuals.com

5. Measure the clearance between the shift fork, the

5th/reverse shift piece and shift piece.

Standard:
0.2-0.5
mm

(0.008-0.020
in)

Service Limit: 0.6 mm (0.024 in)

1ST/2ND SHIFT FORK

5TH/REVERSE

SHIFT PIECE

6. If the
clearance exceeds
the
service
limit,
measure

the width of the shift piece.

Standard: 11.9 - 12.0 mm (0.469-0.472 in)

SHIFT PIECE

If the width of the shift piece is less than the stan-

dard, replace the shift piece with a new one.

If the width of the shift piece is within the standard,

replace the 5th/reverse shift piece or shift forks

with a new one.
3RD/4TH

SHIFT FORK

SHIFT PIECEProCarManuals.com

Shift Fork, Synchro

Sleeve

Clearance Inspection

1. Measure the clearance between each shift fork and

its matching synchro sleeve.

Standard:
0.45-0.65
mm

(0.018-0.026 in)

Service Limit: 1.0 mm (0.039 in)

SYNCHRO

SLEEVE

SHIFT FORK

2. If the clearance exceeds the service limit, measure

the width of the shift fork fingers.

Standard:

1st/2nd
Shift
Fork:
8.9-9.0
mm

(0.350-0.354 in)

3rd/4th
Shift
Fork:
7.4-7.5
mm

(0.291 - 0.295 in)

5th Shift Fork: 6.4—6.5 mm

(0.252-0.256 in)

SHIFT FORK

If the width of the shift fork fingers is less than the

standard, replace the shift fork with a new one.

If the width of the shift fork fingers is within the

standard, replace the synchro sleeve with a new

one.

NOTE: The synchro sleeve and synchro hub

should be replaced as a set.ProCarManuals.com

Mainshaft Assembly

Clearance Inspection

1. Measure the clearance between 2nd and 3rd gears.

Standard: 0.06 — 0.21 mm

(0.002-0.008
in)

Service Limit: 0.3 mm (0.012 in)

2ND GEAR

3RD GEAR

2. If the clearance exceeds the service limit, measure

the thickness of 3rd gear.

Standard: 35.92 — 35.97 mm

(1.414-1.416 in)

Service Limit: 35.80 mm (1.409 in)

3RD GEAR

If the thickness of 3rd gear is less than the service

limit, replace 3rd gear with a new one.

If the thickness of 3rd gear is within the service

limit, replace the 3rd/4th synchro hub with a new

one.
3. Measure the clearance between 4th gear and the

spacer collar.

Standard: 0.06—0.21 mm

(0.002-0.008
in)

Service Limit: 0.3 mm (0.012 in)

4TH GEAR

5TH GEAR

4. If the clearance exceeds the service limit, measure

distance on the spacer collar.

Standard: 29.53 — 29.58 mm

(1.163-1.165 in)

Service Limit: 29.51 mm (1.162 in)

SPACER

COLLAR
4TH GEAR

"SIDE

5. If distance is less than the service limit, replace

the spacer collar with a new one.

If
distance
is
within
the
service
limit,
measure

the thickness of 4th gear.

Standard: 35.92-35.97 mm

(1.414-1.416 in)

Service Limit: 35.80 mm (1.409 in)

If the thickness of 4th gear is less than the service

limit,
replace
4th
gear
with
a new
one.

If the thickness of 4th gear is within the service

limit, replace the 3rd/4th synchro hub with a new

one.
4TH

GEARProCarManuals.com

6. Measure the clearance between the spacer collar

and 5th gear.

Standard: 0.06—0.21 mm

(0.002-0.008
in)

Service Limit: 0.3 mm (0.012 in)

4TH GEAR

5TH GEAR

7. If the clearance exceeds the service limit, measure

distance on the spacer collar.

Standard: 28.53—28.58 mm

(1.123-1.125 in)

Service Limit: 28.51 mm (1.122 in)

5TH GEAR

SIDE
SPACER

COLLAR

8. If distance is less than the service limit, replace

the spacer collar with a new one.

If distance is within the service limit, measure

thickness of 5th gear.

Standard: 34.92-34.97 mm

(1.375-1.377 in)

Service Limit: 34.80 mm (1.370 in)

5TH GEAR

If the thickness of 5th gear is less than the service

limit, replace 5th gear with a new one.

If the thickness of 5th gear is within the service

limit, replace the 5th synchro hub with a new one.ProCarManuals.com