Isuzu N-Series. Service manual - part 139

3C-4 FRONT SUSPENSION

ON-VEHICLE SERVICIE

Front Suspension (Rigid Suspension)

Leaf Spring

Legend

A. NHR and NKR

5. Bolt

B. NPR, NQR and NPS

6. Rubber bushing

1. Shock absorber

7. Shackle pin, nut and washer

2. U-bolt and nut

8. Shackle

3. Helper rubber

9. Rubber bushing

4. Spring pin, nut and washer

10. Leaf spring

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Removal

Preparation
Make the following preparation before removing the leaf
spring.

1. Brace the rear wheels.
2. Jack up the front axle until the front wheels are lift-

ed off the ground and position safety stand under
the chassis frame.
Refer to “Lifting Instruction” in Section 0A for ac-
ceptable lifting point and supportable point loca-
tion.

3. Position a garage jack under the front axle.
4. For the vehicle model with a stabilizer, remove the

mounting portion on the axle side of the stabilizer
in advance before removing the leaf spring. (Refer
to the removal procedure of the stabilizer.)

NHR and NKR

1. Shock Absorber
2. U-bolt and Nut
3. Helper Rubber

If the U-bolts are heavily rusted, apply a generous
amount of oil to the threads before loosening them
to prevent seizure.

4. Spring Pin, Nut and Washer
5. Bolt
6. Rubber Bushing

Take out the rubber bushings after removal of the
spring pin.

7. Shackle Pin, Nut and Washer
8. Shackle
9. Rubber Bushing

Take out the rubber bushings after removal of the
shackle.

10. Leaf Spring

Lower the garage jack slowly and remove the front
spring assembly. When removing the front spring
assembly, exercise care not to cause damage to
the brake flexible hoses and drag link. AIso, exer-
cise care not to cause the spring to come down.

NPR, NQR and NPS

1. Shock Absorber
2. U-bolt and Nut

Refer to page NHR and NKR.

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3. Helper Rubber
4. Spring Pin, Nut and Washer

Drive out the spring pin with a hammer using a
brass bar after removal of the spring pin nut.

5. Shackle Pin, Nut and Washer
6. Shackle

Drive out the shackle pin with a hammer using a
brass bar after removal of the shackle pin nut.

7. Rubber Bushing
8. Leaf Spring

Refer to NHR and NKR.

Inspection and Repair

Make the necessary adjustments, repairs and part re-
placements if excessive wear or damage is discovered
during inspection.
Visual Check
Inspect the following parts for wear, damage or other ab-
normal conditions.

• Leaf spring assembly
• Clip
• Center  bolt
• U-bolt
• Spring pin
• Shackle pin
• Helper rubber
• Rubber bushing

Shock Absorber

1. Inspect for extreme oil leakage.

Slight oil leakage is allowed.

2. Inspect for temperature after running.

Unchanged temperature indicates deteriorated
function.

3. Inspect if large resistance is felt when the shock

absorber is expanded and contracted by holding
either end, or if play is eliminated after several
times of expansion and contraction.
The function has deteriorated if the above condi-
tion is not observed.

4. Inspect the bushing for wear or deterioration.

Replace if abnormality is found.

Leaf Spring Assembly Replacement

• Apply a setting mark (1) across the springs before

disassembling the leaf spring assembly.

• Apply grease to both faces of each leaf spring at

reassembly.

• Use a bench press for disassembly and reassem-

bly.

• Discard center bolt and install a new one.

When replacing the leaf spring assembly, use the leaf
spring with the same camber represented by “+, -, I” on
both right and left sides.

Center Bolt
Tighten the center bolt nut to the specified torque.

Tighten:

• Center bolt to 39 N

⋅m (4 kg⋅m/29 lb⋅ft)

Bushing Replacement
When replacing bushing, drive out the bushing using a
bench press.
Leaf Spring Rubber Bush Remover & Installer:
5-8840-2048-1
Leaf Spring Metal Bush Remover & Installer:
5-8840-2049-1

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Installation

NHR and NKR

1. Leaf Spring

Install the leaf spring assembly with the camber
mark (1) turned to front side (2) on the front axle.

2. Helper Rubber
3. U-Bolt and Nut

Position the U-bolts and helper rubber on the leaf
spring assemblies and jack up the front axle.
When tightening the nuts, apply oil as necessary to
prevent damaging the threads.

Tighten:

• U-bolt nut to 127 N

⋅m (13 kg⋅m/94 lb⋅ft)

4. Rubber Bushing
5. Spring Pin, Nut and Washer
6. Bolt

Finger tighten first, and tighten to specified torque
after lowering the vehicle to ground.

Tighten:

• Spring pin bolt and nut to 

Bolt: 27 N

⋅m (2.8 kg⋅m/20 lb⋅ft)

Nut: 177 N

⋅m (18 kg⋅m/130 lb⋅ft)

7. Rubber Bushing
8. Shackle
9. Shackle Pin, Nut and Washer

Finger tighten first, and tighten to specified torque
after lowering the vehicle to ground.

Tighten:

• Shackle pin nut to 137 N

⋅m (14 kg⋅m /101 lb⋅ft) 

10. Shock Absorber

Tighten:

• Shock absorber nut to

Upper nut: 21 N

⋅m (2.1 kg⋅m/16 lb⋅ft)

Lower nut: 61 N

⋅m (6.2 kg⋅m/45 lb⋅ft)

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