ACURA NSX 1991 Service Repair Manual

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

Reverse Idler Gear Shaft

Assembly

Removal

1. Remove the reverse shift arm from the clutch

housing.

REVERSE SHIFT

ARM

CLUTCH HOUSING

2. Shift the reverse shift fork to the driven gear side.

3. Lift the mainshaft assembly and reverse idler gear

shaft assembly, then remove the reverse shift fork

assembly.

REVERSE SHIFT

FORK ASSEMBLYProCarManuals.com

4. Lift the reverse idler gear shaft, then remove the

spring pin from the groove and remove the idler

gear shaft assembly.

REVERSE IDLE GEAR

SHAFT ASSEMBLY

SPRING PINProCarManuals.com

Disassembly/Reassembly
NOTE:
• Th e thrus t needl e bearin g ar e th e sam e size .
• Th e needl e bearin g ar e th e sam e size .
Prior t o reassembling , clea n al l th e part s
in solvent , dr y them , an d appl y lubrican t
to an y contac t surface .
22 x 3 8 x 3 m m THRUS T WASHER
THRUS T NEEDL E BEARIN G
Inspect fo r wea r an d operation .
REVERSE DRIVE N GEA RInspec t fo r wea r an d damage .
NEEDLE BEARIN GInspect fo r wea r an d operation .
THRUST NEEDL E BEARIN GInspect fo r wea r an d operation .
SYNCHRO SPRIN G
SYNCHR O RIN G
Inspection , pag e 13-3 5
REVERS E SYNCHR O SLEEV E
Inspection , pag e 13-13
REVERS E IDL E GEA R SHAF TInspect fo r wea r an d damage .
3 x 6 mm SPRIN G PI NReplace .
THRUST NEEDL E BEARIN GInspect fo r wea r an d operation .
NEEDLE BEARIN GInspect fo r wea r an d operation .
REVERSE DRIV E GEA RInspec t fo r wea r an d damage .
THRUST NEEDL E BEARIN GInspect fo r wea r an d operation .
22 x 38 x 2. 2 m mTHRUS T WASHE R
SPRIN G WASHE R
ProCarManuals.com

Mainshaft, Countershaft,

Differential Assemblies

Removal

1. Remove the change holder assembly from the

clutch housing.

CLUTCH

HOUSING
CHANGE HOLDER

ASSEMBLY

2. Remove the mainshaft assembly and countershaft

assembly with the shift fork from the clutch

housing.

NOTE: Tape the mainshaft splines to protect them

before removing the mainshaft and countershaft

assemblies.

MAINSHAFT

ASSEMBLY
COUNTERSHAFT

ASSEMBLY

SHIFT FORK

ASSEMBLY

Tape the mainshaft

splines.

SPRING

WASHER

CLUTCH HOUSINGProCarManuals.com

3. Remove the differential assembly from the clutch

housing.

DIFFERENTIAL ASSEMBLY

CLUTCH

HOUSINGProCarManuals.com

Shift Lever,

Select Lever

Removal

1. Remove the shift spring set plate and shift detent

spring from the transmission housing.

TRANSMISSION

HOUSING
SHIFT SPRING

SET PLATE

SHIFT DETENT

SPRING

2. Remove the bolt and spring washer.

3. Pull out the shift lever, then remove the shift arm.

SPRING WASHER
SHIFT ARM

SHIFT LEVER
OIL SEAL

Replace.ProCarManuals.com

Shift Lever, Select Lever

Removal

4. Remove the bolt and spring washer.

5. Pull out the select lever, then remove the select

arm.

SPRING WASHER
SELECT ARM

OIL SEAL

Replace.

SELECT LEVERProCarManuals.com

Change Holder Assembly

Disassembly/Reassembly

NOTE: Make sure the return springs are installed properly.

Prior to reassembling, clean all parts in solvent, dry them, and apply lubricant to any contact surfaces.

SHIFT PIECE

LOCK COLLAR
SHIFT PIECE SHAFT

INTERLOCK

CHANGE HOLDER

SELECT RETURN SPRING

5TH/REVERSE RETURN SPRING

3 x 16 mm SPRING PIN

Replace.ProCarManuals.com