Isuzu N-Series. Manual - part 854

MANUAL TRANSMISSION 7B-77

8. Remove from the main shaft the following parts us-

ing a bearing remover with a press; the collar, 3rd
gear, needle bearing, 3rd inside ring, 3rd outside
ring, 3rd block ring, 2nd-3rd clutch hub assembly &
sleeve, 2nd block ring, 2nd outside ring, 2nd inside
ring, 2nd gear, needle bearing.

9. Disassemble the 2nd-3rd clutch hub assembly &

sleeve.

Inspect each part. If any wear, damage or other abnor-
mality is found, repair or replace the part.
10. Inspect each bearing with respect to the following

items. If any abnormality is found, replace the item.

• Smoothness of rotation

• Noise
• Abnormal external appearance, including dam-

age, rust, etc.

11. Inspect the inside diameter of the gear.

• Measure the inside diameter of each gear us-

ing an inside dial gauge.

• If the measured value exceeds the limit, re-

place the gear.

12. Inspect the deflection of the main shaft.

• Measure the deflection of the main shaft using

a dial gauge.

• If the measured value exceeds the limit, re-

place the main shaft.
Standard: 0.015 mm (0.00059 in)
Limit: 0.1 mm (0.00393 in)

Legend

1. Clutch hub
2. Sleeve
3. Ball
4. Block
5. Spring

N7A1199E

N7A1200E

Gear Inside Diameter, mm (in)

Standard

Limit

6th gear

50.009 — 50.025 

(1.968 — 1.969)

50.065 

(1.971)

4th gear

44.009 — 44.025 

(1.732 — 1.733)

44.065 

(1.734)

3rd gear

63.010 — 63.029 

(2.480 — 2.481)

63.069 

(2.483)

2nd gear

63.010 — 63.029 

(2.480 — 2.481)

63.069 

(2.483)

1st gear

63.010 — 63.029 

(2.480 — 2.481)

63.069 

(2.483)

Reverse Gear

63.010 — 63.029 

(2.480 — 2.481)

63.069 

(2.483)

N7A1201E

7B-78 MANUAL TRANSMISSION

13. Inspect the synchromesh system.

• Inspect the components. Repair the slight

stepped wear and damage using an oil stone or
a pencil grinder.

14. Measure the clearance between the block ring and

the dog gear using a thickness gauge.

• If the measured value exceeds the limit, re-

place the block gear.

15. Inspect the sliding part, spline part, inserting part

and insert groove of the clutch hub and sliding
sleeve for wear and damage.

16. Measure the free play in the direction of spline ro-

tation on the clutch hub external circumference.

• If the measured value exceeds the limit, re-

place the part.

Clearance between Block Ring and Dog Gear, mm
(in)

Standard

Limit

4th / 5th / 6th / 

Reverse

1.30 — 2.60 

(0.051 — 0.102)

0.5 (0.019)

2nd / 3rd

1.00 — 2.50 

(0.039 — 0.098)

0.5 (0.019)

1st

1.00 — 2.50 

(0.039 — 0.098)

0.5 (0.019)

N7A1202E

N7A1203E

Legend

1. Block ring
2. Outside ring
3. Inside ring

Spline Free Play, mm (in)

Standard

Limit

0 — 0.05 (0 — 0.0019)

0.3 (0.0118)

N7A1204E

N7A1205E

MANUAL TRANSMISSION 7B-79

17. Measure the clearance between the insert and

block ring groove using a caliper.

• If the measured value exceeds the limit, re-

place the insert and block ring.

18. Measure the clearance between the insert and

clutch hub using a thickness gauge.

• If the measured value exceeds the limit, re-

place the insert and clutch hub.

19. Measure the clearance between the block ring and

the clutch hub using a thickness gauge.

• If the measured value exceeds the limit, re-

place the block and clutch hub.

Assembly

• Clean up each part.
• Set the main shaft in a vise, with the long spline

part at the bottom.

Clearance between Insert and Block Ring Groove,
mm (in)

Standard

4th / 5th / 6th

3.46 — 3.76 (0.136 — 0.148)

Clearance between Insert and Clutch Hub, mm (in)

Standard

4th / 5th / 6th

0.01 — 0.21 (0.00039 — 0.00826)

N7A1206E

N7A1207E

Clearance between Block Ring and Clutch Hub, mm
(in)

Standard

2nd / 3rd

4.30 — 4.70 (0.16929 — 0.18503)

1st / Reverse

4.30 — 4.70 (0.16929 — 0.18503)

Legend

1. Block ring
2. Clutch hub

N7A1208E

N7A1209E

7B-80 MANUAL TRANSMISSION

When setting the main shaft, make sure not to
damage the grind surface.

1. Assemble the 2nd-3rd clutch hub assembly &

sleeve following the procedure below.
a. Install the block and sleeve to the clutch hub.
b. Inside the sleeve, there are three ball grooves.

Align the phase to let the ball enter the center
of the ball grooves.

c. Insert sleeve (1) until the clutch hub (5) slightly

overlaps the block.

d. Securely insert the sleeve until the ball enters

the ball groove of the sleeve by pushing the ball
(2), block (3) and spring (4).

2. Apply engine oil 5W-30 to the needle bearing, 2nd

gear thrust surface and synchro cone taper sur-
face. And install the 2nd gear (6) and needle bear-
ing (5) to the main shaft with the dog gear turned
upward.

3. Install the 2nd inside ring (4), 2nd outside ring (3)

and 2nd block ring (2) inserting the nail of the out-

side ring into the gear hole of the 2nd gear. At this
time, make sure to apply engine oil 5W-30 suffi-
ciently to the both sides of the inside ring and out-
side ring, and inside diameter surface of the block
ring.

4. Insert the 2nd-3rd clutch hub assembly & sleeve

with a press using the installer 5-8840-2345-0, set-
ting the six nails of the inside ring to enter the six
holes of the hub.

5. During installation, set the six nails of the inside

ring of the 3rd block ring (7), 3rd outside ring (6)
and 3rd inside ring (5) to enter the six hub holes, re-
spectively. At this time, apply engine oil 5W-30 suf-
ficiently to the inside surface of the outside ring and
the inside diameter surface of the block ring.

6. Apply engine oil 5W-30 to the needle bearing, 3rd

gear thrust surface and synchro cone taper. Turn
the dog gear downward, and insert the 3rd gear
(4), needle bearing (3) and collar (2) using the in-
staller 5-8840-2345-0 with a press, setting the nail
of the outer ring to enter the dog gear hole of the
3rd gear.

7. Install the snap ring (1) using snap ring pliers.

Caution:
Replace deformed or damaged snap rings with new
ones. Check that the parts are securely installed.

N7A1210E

N7A1211E

N7A1212E