air suspension ISUZU TROOPER 1998 Service User Guide

FRONT SUSPENSION 3C – 23
1. Nut and Cotter Pin
Remove the upper ball joint from the knuckle.
Remover: 5-8840-2121-0 (J-36831)
CAUTION:
Be careful not t o break the ball joint boot.
2. Bolt, Nut and Washer
3. Upper Ball Joint
INSPECTION AND REPAIR
Make necessary parts replacement if wear, damage,
corrosion or any other abnormal conditions are found
through inspection.
Inspect the lower end boot for damage or grease leak.
Move the ball joint as shown in the figure to confirm its
normal movement.
Inspect screw/taper area of ball for flaws.
If any defects are found by the above inspections, replace
the ball joint assembly with new one.
After moving the ball joint 4 or 5 times, attach nut then
measure the preload.
Upper Ball Joint Preload N·m (kg·m/lb·in)
0.5 – 3.2 (0.05 – 0.33 / 4.3 – 28.6)
If the above limits specified are exceeded, replace the
ball joint assembly.

3C – 26 FRONT SUSPENSION
1. Nut and Cotter Pin
Remove the upper ball joint from the knuckle.
Remover: 5-8840-2005-0 (J-29107)
CAUTION:
Be careful not to break the ball joint boot.
2. Nut
3. Lower Ball Joint
4. Bolt
INSPECTION AND REPAIR
Make necessary parts replacement if wear, damage,
corrosion or any other abnormal conditions are found
through inspection.
Inspect the lower end boot for damage or grease leak.
Move the ball joint as shown in the figure to confirm its
normal movement.
Inspect screw/taper area of ball for flaws.
If any defects are found by the above inspections, replace
the ball joint assembly with new one.
After moving the ball joint 4 or 5 times, attach nut then
measure the preload.
Lower Ball Joint Preload N·m (kg·m/lb·in)
0.5 – 6.4 (0.05 – 0.65 / 4.3 – 56.4)
If the above limits specified are exceeded, replace the
ball joint assembly.

3D – 4 REAR SUSPENSION; COIL SPRING
INSTALLATION
5. Coil Spring
Make sure that the coil spring is installed in the proper
position.
REMOVAL
Preparation:
1) Raise the vehicle and support the frame with suitable
safety stands.
2) Support the rear axle case with a jack.
1. Parking Brake Cable Bracket
Remove the parking brake cable from the trailing link.
2. Stabilizer Bar
Disconnect the stabilizer bar at the stabilizer link.
3. Shock Absorber
Remove the shock absorber from the axle case.
4. Insulator
5. Coil Spring
Remove the insulator and coil spring while lowering
the rear axle case.
CAUTION:
Be sure not to let the brake hose, parking brake cable,
and breather hose extend to their full length.
INSPECTION AND REPAIR
Make necessary correction or parts replacement if wear,
damage, corrosion or any other abnormal condition are
found through inspection.
•Coil spring
•Insulator
Fit the end of the coil spring to the coil spring seat and
mount the coil spring on the rear axle case.

REAR SUSPENSION; COIL SPRING 3D – 7
REMOVAL
1. Nut and Washer
2. Bolt, Nut and Washer
3. Shock Absorber
INSPECTION AND REPAIR
Make necessary correction or parts replacement if wear,
damage, corrosion or any other abnormal condition are
found through inspection.
•Shock absorber
•Rubber bushing (Axle side)
INSTALLATION
3. Shock Absorber
NOTE:
When mounting rubber bushings, be sure not to use
grease on bushings or any other nearby part.
2. Bolt, Nut and Washer
NOTE:
Tighten the bolt and nut lightly, and retighten to the
specified torque after the vehicle is at curb height.
Shock Absorber Nut Torque N·m (kg·m/lb·ft)
95 (9.7 / 70)
1. Nut and Washer
NOTE:
Tighten the bolt and nut lightly, and retighten to the
specified torque after the vehicle is at curb height.
Shock Absorber Nut Torque N·m (kg·m/lb·ft)
78 (8.0 / 58)

REAR SUSPENSION; COIL SPRING 3D – 9
INSPECTION AND REPAIR
Make necessary correction or parts replacement if wear,
damage, corrosion or any other abnormal condition are
found through inspection.
1. Trailing Link
2. Rubber Bushing
Remove the rubber bushing.
Remover: 5-8840-2298-0 (J-39214)
Install the rubber bushing.
Installer: 5-8840-2298-0 (J-39214)
NOTE:
When mounting rubber bushings, be sure not to use
grease on bushings or any other nearby part.
INSTALLATION
3. Trailing Link
Make sure that the trailing link is in its correct
position.
NOTE:
When mounting trailing link, be sure not to use
grease on bushings or any other nearby part.
2. Bolt and Nut
NOTE:
Tighten the bolts and nuts lightly, and retighten to
the specified torque after the vehicle is at curb height.
Trailing Link Nut Torque N·m (kg·m/lb·ft)
137 (14.0 / 101)
1. Parking Brake Cable
CAUTION:
The parking brake cable should not be overstrained or
slackened.

REAR SUSPENSION; COIL SPRING 3D – 11
INSPECTION AND REPAIR
Make necessary correction or parts replacement if wear,
damage, corrosion or any other abnormal condition are
found through inspection.
1. Center Link
2. Rubber Bushing
Remove the rubber bushing.
Remover: 5-8840-2298-0 (J-39214)
Install the rubber bushing.
Installer: 5-8840-2298-0 (J-39214)
NOTE:
When mounting rubber bushings, be sure not to use
grease on bushings or any other nearby part.
INSTALLATION
4. Center Link
Make sure that the center link is in its correct position.
NOTE:
When mounting center link, be sure not to use grease
on bushings or any other nearby part.
3. Bolt and Nut
NOTE:
Tighten the bolts and nuts lightly, and retighten to
the specified torque after the vehicle is at curb height.
Center Link Nut Torque N·m (kg·m/lb·ft)
137 (14.0 / 101)
2. Speed Sensor Cable Bracket
1. Speed Sensor Cable

3D – 12 REAR SUSPENSION; COIL SPRING
LATERAL ROD
132
Removal Steps
1. Nut and washer
2. Bolt and nut
3. Lateral rod
Installation Steps
3. Lateral rod
2. Bolt and nut
1. Nut and washer
REMOVAL
1. Nut and Washer
2. Bolt and Nut
3. Lateral Rod
INSPECTION AND REPAIR
Make necessary correction or parts replacement if wear,
damage, corrosion or any other abnormal condition are
found through inspection.
1. Lateral Rod
460RW027

3D – 16 REAR SUSPENSION; COIL SPRING
INSPECTION AND REPAIR
Make necessary correction or parts replacement if wear,
damage, corrosion or any other abnormal condition are
found through inspection.
•Stabilizer bar
•Rubber bushing
•Link ball joint
INSTALLATION
5. Stabilizer Bar
4 Rubber Bushing
3. Bracket
Bracket Bolt Torque N·m (kg·m/lb·ft)
22 (2.2 / 16)
2. Link
1. Nut and Washer
Link Nut Torque N·m (kg·m/lb·ft)
50 (5.1 / 37)

DIFFERENTIAL (FRONT) 4A1±2
Front Drive Axle
Diagnosis
ConditionPossible causeCorrection
Oil Leak At Front AxleWorn or defective oil seal.Replace the oil seal.
Front axle housing cracked.Repair or replace.
Oil Leak At Pinion ShaftToo much gear oil.Correct the oil level.
Oil seal worn or defective.Replace the oil seal.
Pinion flange loose or damaged.Tighten or replace.
Noises In Front Axle Drive Shaft
JointBroken or worn drive shaft joints and
bellows (BJ and DOJ).Replace the drive shaft joints and
bellows.
ªClankº When Accelerating From
ªCoastºLoose drive shaft joint to output shaft
bolts.Tighten.
Damaged inner drive shaft joint.Replace.
Shudder or Vibration During
Acceleration
Excessive drive shaft joint angle.Repair.
AccelerationWorn or damaged drive shaft joints.Replace.
Sticking spider assembly (inner drive
shaft joint).Lubricate or replace.
Sticking joint assembly (outer drive
shaft joint).Lubricate or replace.
Vibration At Highway SpeedsOut of balance or out of round tires.Balance or replace.
Front end out of alignment.Align.
Noises in Front AxleInsufficient gear oil.Replenish the gear oil.
Wrong or poor grade gear oil.Replace the gear oil.
Drive pinion to ring gear backlash
incorrect.Adjust the backlash.
Worn or chipped ring gear, pinion
gear or side gear.Replace the ring gear, pinion gear or
side gear.
Pinion shaft bearing worn.Replace the pinion shaft bearing.
Wheel bearing worn.Replace the wheel bearing.
Differential bearing loose or worn.Tighten or replace.
Wanders and PullsWheel bearing preload too tight.Adjust the wheel bearing preload.
Incorrect front alignment.Adjust the front alignment.
Steering linkage loose or worn.Tighten or replace.
Steering gear out of adjustment.Adjust or replace the steering gear.
Tire worn or improperly inflated.Adjust the inflation or replace.
Front or rear suspension parts loose
or broken.Tighten or replace.
Front Wheel ShimmyWheel bearing worn or improperly
adjusted.Adjust or replace.
Incorrect front alignment.Adjust the front alignment.
Worn ball joint or bush.Replace the ball joint or bush.
Steering linkage loose or worn.Tighten or replace.
Steering gear out of adjustment.Tighten or replace.
Tire worn or improperly inflated.Replace or adjust the inflation.
Shock absorber worn.Replace the shock absorber.

DIFFERENTIAL (REAR 220mm)
4A2A±3
Diagnosis
Many noises that seem to come from the rear axle
actually originate from other sources such as tires, road
surface, wheel bearings, engine, transmission, muffler, or
body drumming. Investigate to find the source of the
noise before disassembling the rear axle. Rear axles, like
any other mechanical device, are not absolutely quiet but
should be considered quiet unless some abnormal noise
is present.
To make a systematic check for axle noise, observe the
following:
1. Select a level asphalt road to reduce tire noise and
body drumming.
2. Check rear axle lubricant level to assure correct level,
and then drive the vehicle far enough to thoroughly
warm up the rear axle lubricant.
3. Note the speed at which noise occurs. Stop the
vehicle and put the transmission in neutral. Run the
engine speed slowly up and down to determine if the
noise is caused by exhaust, muffler noise, or other
engine conditions.
4. Tire noise changes with different road surfaces; axle
noises do not. Temporarily inflate all tires to 344 kPa
(3.5kg/cm
2, 50 psi) (for test purposes only). This will
change noise caused by tires but will not affect noise
caused by the rear axle.
Rear axle noise usually stops when coasting at
speeds under 48 km/h (30 mph); however, tire noise
continues with a lower tone. Rear axle noise usually
changes when comparing pull and coast, but tire
noise stays about the same.
Distinguish between tire noise and rear axle noise by
noting if the noise changes with various speeds or
sudden acceleration and deceleration. Exhaust and
axle noise vary under these conditions, while tire
noise remains constant and is more pronounced at
speeds of 32 to 48 km/h (20 to 30 mph). Further check
for tire noise by driving the vehicle over smooth
pavements or dirt roads (not gravel) with the tires at
normal pressure. If the noise is caused by tires, it will
change noticeably with changes in road surface.
5. Loose or rough front wheel bearings will cause noise
which may be confused with rear axle noise; however,
front wheel bearing noise does not change when
comparing drive and coast. Light application of the
brake while holding vehicle speed steady will often
cause wheel bearing noise to diminish. Front wheel
bearings may be checked for noise by jacking up the
wheels and spinning them or by shaking the wheels to
determine if bearings are loose.
6. Rear suspension rubber bushings and spring
insulators dampen out rear axle noise when correctly
installed. Check to see that there is no link or rod
loosened or metal±to±metal contact.
7. Make sure that there is no metal±to±metal contact
between the floor and the frame.
After the noise has been determined to be in the axle, the
type of axle noise should be determined, in order to make
any necessary repairs.
Gear Noise
Gear noise (whine) is audible from 32 to 89 km/h (20 to 55
mph) under four driving conditions.
1. Driving under acceleration or heavy pull.
2. Driving under load or under constant speed.
3. When using enough throttle to keep the vehicle from
driving the engine while the vehicle slows down
gradually (engine still pulls slightly).
4. When coasting with the vehicle in gear and the throttle
closed. The gear noise is usually more noticeable
between 48 and 64 km/h (30 and 40 mph) and 80 and
89 km/h (50 and 55 mph).
Bearing Noise
Bad bearings generally produce a rough growl or grating
sound, rather than the whine typical of gear noise.
Bearing noise frequently ªwow±wowsº at bearing rpm,
indicating a bad pinion or rear axle side bearing. This
noise can be confused with rear wheel bearing noise.
Rear Wheel Bearing Noise
Rear wheel bearing noise continues to be heard while
coasting at low speed with transmission in neutral. Noise
may diminish by gentle braking. Jack up the rear wheels,
spin them by hand and listen for noise at the hubs.
Replace any faulty wheel bearings.
Knock At Low Speeds
Low speed knock can be caused by worn universal joints
or a side gear hub counter bore in the cage that is worn
oversize. Inspect and replace universal joints or cage and
side gears as required.
Backlash Clunk
Excessive clunk on acceleration and deceleration can be
caused by a worn rear axle pinion shaft, a worn cage,
excessive clearance between the axle and the side gear
splines, excessive clearance between the side gear hub
and the counterbore in the cage, worn pinion and side
gear teeth, worn thrust washers, or excessive drive pinion
and ring gear backlash. Remove worn parts and replace
as required. Select close±fitting parts when possible.
Adjust pinion and ring gear backlash.