Isuzu N-Series. Manual - part 960

7B-76 Automatic Transmission (Smoother)

43. Inspect the speedometer driven gear and driven

gear bushing for wear. 

• Replace if there is excessive wear.

44. Measure the gap between the insert key and the

block ring groove. 

• Use a caliper to measure the gap. 
• If the measured value exceeds the limit,

replace the insert key and block ring.

Assembly

1. Inspect the oil seal. If it needs to be replaced due

to wear or damage, apply engine oil or grease to
the oil seal’s outer circumference, and then use an
installer (5-8840-2756-0) and grip (5-8840-0007-0)
to press-fit it into the clutch housing as shown in
the illustration, taking care that the front-back
orientation of the front oil seal is correct. 

• Fill the lip of the oil seal with Besco L2 grease. 

Caution:
Take care to avoid damaging the oil seal lip. 

Gap Between the Insert Key and Block Ring Groove 

(mm) 

Specified Value

6th

3.46 — 3.76

N7A1100E

N7A1101E

Automatic Transmission (Smoother) 7B-77

 

2. Inspect the counter shaft front bearing. If it needs

to be replaced with a new one due to wear or
damage, use a grip (5-8840-0007-0) and installer
(5-8840-2026-0) to press-fit the bearing outer race. 

3. Inspect the clutch housing bushing. If it needs to be

replaced with a new one due to wear or damage,
use an installer (5-8840-2755-0) to press-fit. 

• Before installing, carefully remove all

protrusions from the bore side of the old
caulking. 

Legend

1. Front Oil Seal

3. ENG Mark

2. T/M Mark

N7A1102E

N7A1103E

N7A1104E

7B-78 Automatic Transmission (Smoother)

• Before installing, carefully caulk at three points,

avoiding the old caulking points and grooves. 

• For the second and subsequent press-fitting,

the notched part should face in the direction of
the clutch housing. 

• After press-fitting, check that the shift rod slides

smoothly. 

4. Install the main shaft assembly, top gear shaft

assembly, and counter shaft assembly. 
a. Use a lashing belt or some other belt from a

lashing device to bundle the main shaft
assembly, counter shaft assembly, and top
gear shaft assembly at two points so they
cannot separate. Tighten the belt securely.
When handing the top gear shaft, take care that
it does not drop. 

b. Stand the top gear shaft assembly, main shaft

assembly, and counter shaft assembly on a
support stand with the top gear shaft assembly
on top. 

c. Wrap the main shaft with tape to avoid damage

to the front oil seal. 

d. While using snap ring pliers to open the top

gear shaft bearing outer snap ring, which
already has been set on the clutch housing,
insert the top gear shaft, counter shaft, and
shaft rod into their appropriate positions in the
clutch housing. 

Caution:

• Confirm that the snap ring is installed properly. 

N7A1105E

N7A1106E

N7A1107E

N7A1108E

Automatic Transmission (Smoother) 7B-79

• Work carefully in order to avoid damaging the front

oil seal. 

5. Install the magnet in the clutch housing. 
6. Inspect the 3rd — 2nd shift arm bushing. If it needs

to be replaced with a new one due to wear or
damage, use an installer (3-8840-2755-0) to press-
fit with a press. 

7. Inspect the 4th — 5th shift arm bushing. If it needs

to be replaced with a new one due to wear or
damage, use an installer (5-8840-2755-0) to press-
fit with a press. 

• Before installing, carefully remove all

protrusions from the bore side of the old
caulking. 

• Press-fit the shift arm bushing taking care to

use the correct orientation and angle. Caulk at
three points, avoiding the bushing gap and old
caulking. 

• After press-fitting, check that the shift rod slides

smoothly. 

8. Install the 1st — Reverse and 2nd — 3rd shift rod

(1) on the 1st — Reverse 6th shift block (5), 2nd —
3rd shift arm (4), 1st — Reverse shift arm (2). 

• Use a hammer to drive the spring pins (3), (6)

into the spring pin holes.

• When press-fitting spring pins, insert a round

bar on the opposite side of the shift rod, and
press-fit while taking care to avoid damage to
other parts. 

N7A1109E

N7A1110E