Isuzu N-Series. Manual - part 946

7B-20 Automatic Transmission (Smoother)

Input Shaft Speed Sensor

Removal

1. Connector
2. Input shaft speed sensor

Inspection

• Replace if the harness, the connector or the seal is

damaged.

• Measure the resistance between terminals.

Replace if the resistance between 1 — 2 is not
within 1.5 to 2.1 k

Ω.

Installation

1. Input shaft speed sensor

• Apply 5W-30 engine oil to the sensor O-ring,

and install. 

Tighten:
9 N

⋅m (0.9 kg⋅m / 6.6 lb⋅ft)

2. Connector

N7A1025E

N7A1026E

Automatic Transmission (Smoother) 7B-21

Turbine Speed Sensor

Removal

1. Connector
2. Turbine speed sensor 

Inspection

• Replace if the harness, the connector or the seal is

damaged.

• Measure the resistance between terminals.

Replace if the resistance between 1 — 2 is not
within 1.5 to 2.1 k

Ω.

Installation

1. Turbine speed sensor 

• Apply oil (Besco ATF III) to the O-ring and

clutch housing hole, and install. 

Tighten:
9 N

⋅m (0.9 kg⋅m / 6.6 lb⋅ft)

2. Connector

N7A1027E

N7A1026E

7B-22 Automatic Transmission (Smoother)

Transmission Fluid Cooler Circuit

Removal

1. Remove the Smoother oil pan drain plug and O-

ring. 

• Drain the oil (Transmission fluid). When

draining the oil, check the oil amount, and
check for metal bits and foreign matter. 

2. Disconnect the transmission fluid cooler pipe

connection. 

3. Remove the transmission fluid cooler pipe from the

clutch housing. 

4. Remove the clip, and remove the transmission fluid

cooler pump. 

Installation

1. Install the transmission fluid cooler pipe in the

clutch housing. 

Tighten:
39 N

⋅m (4.0 kg⋅m / 28.8 lb⋅ft)

Caution:
Use a new gasket. 

2. Connect the transmission fluid cooler pipe. 

Tighten:
44 N

⋅m (4.5 kg⋅m / 32.5 lb⋅ft)

3. Install the clip on the transmission fluid cooler pipe. 

Tighten:
20 N

⋅m (2.0 kg⋅m / 14.8 lb⋅ft)

4. Install the Smoother oil pan drain plug and O-ring. 

Tighten:
40 N

⋅m (4.1 kg⋅m / 29.5 lb⋅ft)

5. Supply transmission fluid (Besco ATF III) from the

oil filler tube to the Smoother. 

Automatic Transmission (Smoother) 7B-23

Flushing The Transmission Fluid Cooler Circuit

Inspection

In order to prevent trouble following Smoother repair,
flushing of the cooler circuit is required when any of the
following conditions exist. 

• When a large volume of debris comes out of the

cooler circuit

• When abnormal wear is discovered while

disassembling the Smoother

• When abnormal wear is discovered in the clutch

facing or when impurities are discovered in the oil 

Procedure 

1. Disconnect the transmission fluid cooler pipe from

the clutch housing and oil cooler. 

2. Use cleaning solvent and pressurized air to clean

the oil cooler and pipes. 

Caution:
The maximum air pressure should be 197kPa {2kg/
cm

2

}.

3. After using the air to dry the cleaning solvent in the

oil cooler and pipes, clean with transmission fluid. 

4. Connect the cooler circuit, and then fill with

transmission fluid. 

Tighten:
44 N

⋅m (4.5 kg⋅m / 32.5 lb⋅ft)

5. Start the engine and check for transmission fluid

leaks from the cooler circuit. 

6. Check the transmission fluid level and replenish if

it is low.