Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 415

5MT-81

Shifter Fork and Rod

MANUAL TRANSMISSION AND DIFFERENTIAL

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

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

Switches and Harness.>

18) Install the manual transmission assembly to the

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

Transmission Assembly.>

C: INSPECTION

1) Check the fork and rod for damage. Replace if it

is damaged.

2) Gearshift mechanism

Repair or replace the gearshift mechanism if ex-

cessively worn, bent or defective in any way.

3) Inspect the clearance between 1st, 2nd driven

gear and reverse driven gear. If any clearance is

not within specifications, replace the shifter fork as

required.
Clearance (a) and (b):

9.5 mm (0.374 in)

4) Inspect the clearance between the 3rd, 4th drive

gear and the coupling sleeve. If any clearance is

not within specifications, replace the shifter fork as

required.
Clearance (a) and (b):

9.3 mm (0.366 in)

(A) 1st driven gear
(B) Reverse driven gear

(C) 2nd driven gear

1st-2nd shifter fork

Part No.

Mark

Remarks

32804AA060

1

Approaches 1st gear
by 0.2 mm (0.008 in)

32804AA070

No mark

Standard

32804AA080

3

Approaches 2nd gear
by 0.2 mm (0.008 in)

MT-01635

(A)

(B)

(a)

(b)

(C)

(A) 3rd drive gear
(B) Coupling sleeve

(C) 4th drive gear

3rd-4th shifter fork

Part No.

Mark

Remarks

32810AA061

1

Approaches 4th gear
by 0.2 mm (0.008 in)

32810AA071

No mark

Standard

32810AA101

3

Approaches 3rd gear
by 0.2 mm (0.008 in)

MT-00940

(A)

(B)

(C)

(a)

(b)

5MT-82

Shifter Fork and Rod

MANUAL TRANSMISSION AND DIFFERENTIAL

5) Inspect the clearance between 5th drive gear

and coupling sleeve. If any clearance is not within

specifications, replace the shifter fork as required.
Clearance (a):

9.3 mm (0.366 in)

6) Inspect the rod end clearances (A) and (B). If

any clearance is not within specifications, replace

the rod or fork as required.
Clearance (A):

3rd-4th — 5th

0.5 — 1.3 mm (0.020 — 0.051 in)

Clearance (B):

1st-2nd — 3rd-4th

0.4 — 1.4 mm (0.016 — 0.055 in)

(A) 5th drive gear
(B) Coupling sleeve

5th shifter fork

Part No.

Mark

Remarks

32812AA201

7

Approaches 5th gear
by 0.2 mm (0.008 in)

32812AA211

No mark

Standard

32812AA221

9

Moves away from 5th
gear by 0.2 mm (0.008
in)

MT-01512

(A)

(B)

(a)

MT-00316

(B)

(A)

5MT-83

General Diagnostic Table

MANUAL TRANSMISSION AND DIFFERENTIAL

20.General Diagnostic Table

A: INSPECTION

1. MANUAL TRANSMISSION

Symptoms

Possible cause

Corrective action

1. Gears are difficult to intermesh.
NOTE:

The cause for difficulty in shifting gears
can be classified into two types: One is a
defective gear shift system and the other
is defective transmission. However, if the
operation is heavy and engagement of the
gears is difficult, a defective clutch disen-
gagement may also be responsible.
Check whether the clutch is correctly
functioning, before checking the gear shift
system and transmission.

(a) Worn, damaged or burred chamfer at
internal spline of the sleeve and reverse
driven gear

Replace.

(b) Worn, damaged or burred chamfer of
gear spline

Replace.

(c) Worn or scratched bushings

Replace.

(d) Incorrect contact or wear between
synchronizer ring and gear cone

Repair or replace.

2. Gear slip-out
• Gear slips out when coasting on rough
road
• Gear slips out during acceleration

(a) Defective pitching stopper adjustment Replace.
(b) Loose engine mounting bolts

Tighten or replace.

(c) Worn shifter fork or broken check ball
spring

Replace.

(d) Worn or damaged ball bearing

Replace.

(e) Excessive clearance between splines
of synchronizer hub and synchronizer
sleeve

Replace.

(f) Worn tooth step of synchronizer hub
(caused by slip-out of 3rd gear)

Replace.

(g) Worn 1st driven gear and driven shaft Replace.
(h) Worn 2nd driven gear and bushing

Replace.

(i) Worn 3rd drive gear and needle bear-
ing

Replace.

(j) Worn 4th drive gear and needle bear-
ing

Replace.

(k) Worn 5th drive gear and needle bear-
ing

Replace.

(l) Worn reverse idler gear and bushing

Replace.

3. Noise emitted from transmission
NOTE:

If a noise is heard when the vehicle is
parked with its engine idling and if a noise
ceases when the clutch is disengaged, it
may be considered that the noise is com-
ing from the transmission.

(a) Insufficient or improper lubrication

Lubricate with specified oil or replace.

(b) Worn or damaged gears and bearings
NOTE:

If the trouble is only wear of the gear teeth
surfaces, only a high whirring noise will
occur at high speeds, but if any part is bro-
ken, rhythmical clicking sounds will be
heard even at low speeds.

Replace.

5MT-84

General Diagnostic Table

MANUAL TRANSMISSION AND DIFFERENTIAL

2. DIFFERENTIAL

Symptoms

Possible cause

Corrective action

1. Broken differential (case, gear, bear-
ing, etc.)
NOTE:

Noise will occur, and eventually the differ-
ential will not be able to operate due to
broken pieces obstructing the gear revo-
lution.

(a) Insufficient or improper oil

Disassemble the differential and replace
broken components. At the same time
check other components for any trouble,
and replace if necessary.

(b) Use of vehicle under severe condi-
tions such as excessive load or improper
use of the clutch

Readjust the preload and backlash of the
bearing, and the contact surface of gear.

(c) Improper adjustment of taper roller
bearing

Adjust.

(d) Improper adjustment of the drive pin-
ion and the hypoid driven gear

Adjust.

(e) Excessive backlash of a vehicle under
severe operating conditions due to worn
differential side gear, washer or differen-
tial pinion

Add recommended oil to the specified
level. Do not use vehicle under severe
operating conditions.

(f) Loose hypoid driven gear clamping
bolts

Tighten.

2. Differential and hypoid gear noises
Troubles of the differential and hypoid
gear always appear as noise problems.
Therefore noise is the first indication of
trouble. However, noises from the engine,
muffler, tire, exhaust gas, bearing, body,
etc. are easily mistaken for the differential
noise. Pay special attention to the hypoid
gear noise because it is easily confused
with other gear noises. There are the fol-
lowing four kinds of noises.
• Gear noise when driving:
If noise increases as the vehicle speed
increases, it may be due to insufficient
gear oil, incorrect gear engagement,
damaged gears, etc.
• Gear noise when coasting:
Damaged gears due to misadjusted bear-
ings and incorrect shim adjustment
• Bearing noise when driving or coasting:
Cracked, broken or damaged bearings
• Noise mainly when turning:
Noise from differential side gear, differen-
tial pinion or differential pinion shaft, etc.

(a) Insufficient oil

Replenish or replace with the specified
amount of recommended oil.

(b) Improper adjustment of hypoid driven
gear and drive pinion

Check the tooth contact.

(c) Worn teeth of hypoid driven gear and
drive pinion

Replace as a set.
Readjust the bearing preload.

(d) Loose roller bearing

Readjust the backlash of the hypoid
driven gear to drive pinion, and check the
tooth contact.

(e) Distorted hypoid driven gear or differ-
ential case

Replace.

(f) Worn washer and differential pinion
shaft

Replace.