Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 406

5MT-45

Center Differential

MANUAL TRANSMISSION AND DIFFERENTIAL

12.Center Differential

A: REMOVAL

1) Remove the manual transmission assembly

from the vehicle. <Ref. to 5MT-23, REMOVAL,

Manual Transmission Assembly.>

2) Remove the back-up light switch and the neutral

position switch. <Ref. to 5MT-33, REMOVAL,

Switches and Harness.>

3) Remove the transfer case together with the ex-

tension case assembly. <Ref. to 5MT-35, REMOV-

AL, Transfer Case and Extension Case

Assembly.>

4) Remove the extension case assembly. <Ref. to

5MT-35, REMOVAL, Transfer Case and Extension

Case Assembly.>

5) Remove the transfer driven gear. <Ref. to 5MT-

43, REMOVAL, Transfer Driven Gear.>

6) Remove the center differential.

B: INSTALLATION

1) Attach the center differential to transfer case.

2) Install the transfer driven gear. <Ref. to 5MT-43,

INSTALLATION, Transfer Driven Gear.>

3) Install the extension case assembly. <Ref. to

5MT-35, INSTALLATION, Transfer Case and Ex-

tension Case Assembly.>

4) Install the transfer case together with the exten-

sion case assembly. <Ref. to 5MT-35, INSTALLA-

TION, Transfer Case and Extension Case

Assembly.>

5) Install the back-up light switch and the neutral

position switch. <Ref. to 5MT-33, INSTALLATION,

Switches and Harness.>

6) Install the manual transmission assembly to the

vehicle. <Ref. to 5MT-26, INSTALLATION, Manual

Transmission Assembly.>

C: DISASSEMBLY

Remove the ball bearing using ST.
NOTE:

Center differential is a non-disassembled part

which should not be disassembled.

ST 498077300

CENTER DIFFERENTIAL

BEARING REMOVER

D: ASSEMBLY

Install the ball bearing to the center differential as-

sembly.
CAUTION:

• Do not apply a load in excess of 10 kN (1 ton,

1.1 US ton, 1.0 Imp ton).

• Use a new ball bearing.

E: INSPECTION

1) Bearing

Replace the bearings in the following cases.

• In case of broken or rusty bearings

• In case of worn or damaged bearings

• When the bearings fail to turn smoothly or emit

noise in rotation after gear oil lubrication.

• When bearing has other defects.

2) Center differential

If there is wear or damage, replace the center dif-

ferential case assembly.

(A) Ball bearing

MT-00147

ST

MT-00148

(A)

5MT-46

Reverse Check Sleeve

MANUAL TRANSMISSION AND DIFFERENTIAL

13.Reverse Check Sleeve

A: REMOVAL

1) Remove the manual transmission assembly

from the vehicle. <Ref. to 5MT-23, REMOVAL,

Manual Transmission Assembly.>

2) Remove the transfer case together with the ex-

tension case assembly. <Ref. to 5MT-35, REMOV-

AL, Transfer Case and Extension Case

Assembly.>

3) Remove the shifter arm.

4) Remove the plug, gasket, reverse accent spring,

and reverse check ball.

5) Remove the reverse check sleeve.

B: INSTALLATION

1) Install the reverse check sleeve.
Tightening torque:

6.4 N·m (0.7 kgf-m, 4.7 ft-lb)

2) Install the reverse check ball, reverse accent

spring, gasket, and plug to the transfer case.
NOTE:

Use a new gasket.
Tightening torque:

9.75 N·m (1.0 kgf-m, 7.2 ft-lb)

3) Attach the shifter arm to the transfer case as-

sembly.

4) Install the transfer case together with the exten-

sion case assembly. <Ref. to 5MT-35, INSTALLA-

TION, Transfer Case and Extension Case

Assembly.>

5) Install the manual transmission assembly to the

vehicle. <Ref. to 5MT-26, INSTALLATION, Manual

Transmission Assembly.>

C: DISASSEMBLY

1) Cover the reverse check sleeve with cloth, and

remove the snap ring by using screwdriver.
NOTE:

If the snap ring is deformed or the spring repulsive

force is not enough, replace with a new snap ring.

MT-00149

MT-00150

MT-00150

(A) Snap ring

MT-00149

MT-00153

(A)

5MT-47

Reverse Check Sleeve

MANUAL TRANSMISSION AND DIFFERENTIAL

2) Remove the reverse check plate, reverse check

spring, reverse check cam, return spring (5th-Re-

verse), reverse accent shaft, return spring cap, and

return spring (1st-2nd).

3) Remove the O-ring.
NOTE:

Be careful not to damage the adjusting shim be-

tween reverse check sleeve assembly and case.

D: ASSEMBLY

1) Install the return spring (1st-2nd), return spring

cap, reverse accent shaft, reverse check cam, re-

turn spring (5th-Reverse) and reverse check spring

to the reverse check sleeve.
NOTE:

Be sure to insert the curved part of reverse check

spring into the check cam groove.

2) Hook the curved part of reverse check spring

onto the reverse check plate.

3) Rotate the cam so that the protrusion on the re-

verse check cam is located at the plate opening.

4) While fixing the cam to that position, attach the

reverse check plate to the reverse check sleeve,

and secure with snap ring.

5) Insert the O-ring into the sleeve groove.
NOTE:

Use new O-rings.

E: INSPECTION

• Make sure the cutout of the reverse accent shaft

is aligned with the opening in the reverse check

sleeve.

• Turn the cam by hand to check for smooth rota-

tion.

• Move the cam and shaft all the way toward the

plate, and make sure it releases.

If the cam does not return properly, replace the re-

verse check spring. If the shaft does not return,

check for scratches on the inner surface of sleeve.

If the sleeve is in good order, replace the spring.

• Select a suitable reverse accent shaft and re-

verse check plate. <Ref. to 5MT-48, ADJUST-

MENT, Reverse Check Sleeve.>

(A) Reverse check plate
(B) Reverse check spring

(C) Return spring (5th-Reverse)
(D) Reverse check cam

(E) Reverse accent shaft

(F) Return spring cap

(G) Return spring (1st-2nd)

(A) Reverse check plate
(B) Reverse check spring

(C) Return spring (5th-Reverse)
(D) Reverse check cam

(E) Reverse accent shaft

(F) Return spring cap

(G) Return spring (1st-2nd)

MT-00154

(B)

(C)

(D)

(E)

(F)

(G)

(A)

MT-00154

(B)

(C)

(D)

(E)

(F)

(G)

(A)

(A) Snap ring
(B) Reverse check plate

(C) Reverse check spring
(D) Reverse check cam

MT-00156

(A)

(D)

(B)

(C)

5MT-48

Reverse Check Sleeve

MANUAL TRANSMISSION AND DIFFERENTIAL

F: ADJUSTMENT

1. NEUTRAL POSITION ADJUSTMENT

1) Shift the gear into 3rd gear position.

2) Because of the return spring, until the arm con-

tacts the stopper the shifter arm will feel lighter

moving towards 1st/2nd gear and heavier towards

the reverse gear.

3) Make adjustment so that the heavy stroke (re-

verse side) is a little heavier than the lighter stroke

(1st/2nd side).

4) To adjust, remove the bolts holding the reverse

check sleeve assembly to the case, and move the

sleeve assembly outward, then place an adjust-

ment shim between the sleeve assembly and the

case to adjust the clearance.
CAUTION:

Be careful not to damage the O-ring when plac-

ing shims.
NOTE:

• When the shim is removed, the neutral position

will move closer to reverse; when the shim is add-

ed, the neutral position will move closer to 1st gear.

• If it is not possible to adjust the clearance with

only shims, replace the reverse accent shaft and

re-adjust.

2. REVERSE CHECK PLATE ADJUST-

MENT

1) Shift the shifter arm to “5th” and then to reverse

to see if the reverse check mechanism operates

properly.

2) Also check to see if the arm returns to neutral

when released from the reverse position. If the arm

does not return properly, replace the reverse check

plate.

Adjusting shim

Part No.

Thickness mm (in)

32190AA000

0.15 (0.0059)

32190AA010

0.30 (0.0118)

Reverse accent shaft

Part No.

Mark

Remarks

32188AA130

S

Neutral position is closer to
1st gear.

32188AA140

T

Standard

32188AA150

U

Neutral position is closer to
reverse gear.

Reverse check plate

Part No.

(A): No. Angle θ

Remarks

32189AA001

0

28°

Arm stops closer to 5th
gear.

32189AA011

1

31°

Arm stops closer to 5th
gear.

32189AA021

2

34°

Arm stops in the center.

32189AA031

3

37°

Arm stops closer to
reverse gear.

32189AA041

4

40°

Arm stops closer to
reverse gear.

MT-00157

(A)