check engine light OPEL FRONTERA 1998 Owners Manual

WIRING SYSTEM 8D–399
1. Check to see if the battery voltage is normal.
2. Check to see if the fuse is normal.
3. Replace the anti–theft & keyless entry control unit with one reserved for test. If a trouble recurs even after replacing
the control unit, find out the cause of the trouble by referring to “System check procedure” and the following list.
ITEM MALFUNCTION POSSIBLE CAUSE DETECTING METHOD REMARKS
ANTI–THEFT
indicator light
does not flash
ANTI–THEFT
indicator light
does not turn off.
(Steadily on)
When door is
opened by pulling
up locking knob,
alarm does not
operate
Alarm does not
stop. Indicator light
does not change
to fully ON
condition, or does
not come on at
all.Burnt out indicator
light bulb possible.
Refer to “Connector
check table” in this
system.
Refer to “Connector
check table” in this
system.
Refer to “Connector
check table” in this
system.
Refer to “Connector
check table” in this
system.
Refer to “Connector
check table” in this
system.
Refer to “Connector
check table” in this
system. Defective contact of door switch,
or open circuit in door switch
wiring.
Short circuit in the detect switch.
Engine hood, doors and tailgate
are not fully closed and locked.
Defective door switch, or short
circuit in switch wiring.
Defective tamper switch, or short
circuit in wiring.
Defective lock switch, or short
circuit in wiring.
Defective engine hood switch, or
short circuit in wiring.
Defective tailgate switch, or short
circuit in wiring.
Defective control unit.
Poor contact of lock switch, or
open circuit in wiring.
Broken wire in wiring to headlight
and horn, or a blown fuse.
Defective contact of detect
switch, or damaged switch wiring.With door open, dome light and
courtesy light do not come on.
Check the control unit connector.
Check to see if doors are closed
and locked.
Dome light and courtesy light
remain lit on after closing doors.
Check the control unit connector.
Check the control unit connector.
Check the control unit connector.
Luggage room light remains lit
after closing tailgate.
Check alarm operation (See No.
46 of “System check procedure”),
possible cause is a poor contact
of lock switch of an open circuit in
wiring.
Check to see if headlights go out.
Check the control unit connector.
Check the control unit connector. A
C
D
E B

8D–400 WIRING SYSTEM
ITEM MALFUNCTION POSSIBLE CAUSE DETECTING METHOD REMARKS
Even when door
unlocked with
key, alarm
operates.
Alarm does not
operate even with
tailgate open.
Even when
tailgate is opened
with key, alarm
does not stop.
Even when
engine hood is
opened with
remote release,
alarm does not
operate
Even when
starter switch is
turned, alarm
does not stop
Indicator light
continues
flashingRefer to “Connector
check table” in this
system.
Refer to “Connector
check table” in this
system.
Refer to “Connector
check table” in this
system. Defective contact of detect
switch, or damaged switch wiring.
Door detect switch is assembled
to wrong door.
Defective contact of tailgate
switch, or defective wiring.
Defective contact of tailgate
detect switch, or damage wiring.
Damaged engine hood switch or
wiring.
Defective contact of starter
switch.
Damaged door switch, or a short
circuit in wiring.
Damaged tamper switch, or a
short circuit in wiring.Check the control unit connector.
When key is turned to lock
position, alarm stops.
When luggage room light switch
is turned on with tailgate open,
luggage room light does not
come on.
Check the control unit connector.
With starter switch turned to
“ACC” position, audio, cigarette
lighter and door mirrors (on
“ACC” circuit) do not operate.
After closing door, dome light and
courtesy light remain on.
Check the control unit connector. F
G
H
I
J
K

WIRING SYSTEM 8D–401
STEP OPERATION ITEM TO BE CHECKEDITEM OF
REMARKS
MALFUNCTION
Be sure to lock door
with locking knob.
Activate alarm
device.
All doors are
unlocked.
With key set at unlock
position, check to see
if alarm stops.
All doors are
locked.
Activate alarm
device.
Activate alarm
device.
Only left rear door
is unlocked. Check to see if engine hood,
tailgate and doors are closed and
locked.
Check to see if indicator light
remains lit off.
Check to see if indicator light
flashes.
Check to see if dome light and
courtesy light illuminate.
Check to see if indicator light
changes from flashing to steadily
on.
Check to see if indicator light
turns off in about 10 seconds.
Check to see if alarm operates
(with headlight flashing, and horn
blaring intermittently.)
Check to see if alarm stops.
Check to see if indicator light
turns on.
Check to see if indicator light
goes off after about 10 seconds.
Check to see if alarm does not
operate.
Check to see if indicator light
turns on.
Check to see if indicator light
goes off after about 10 seconds.
Check to see if alarm starts. Turn starter key to “ON” position.
Open windows fully.
Pull out starter key after turning it
back to “OFF” position.
Unlock left front door with locking
knob.
Open left front door. (And get out
of the vehicle.)
Close left front door.
Lock left front door.
Wait about 10 seconds
Unlock left front door with locking
knob.
Insert key into key cylinder of left
front door and turn it in unlock
direction.
Lock left front door.
Wait for about 10 seconds.
Unlock left front door with key.
Lock left front door with key.
Wait for about 10 seconds.
Unlock left rear door with locking
knob.K
A
B
C
D
E
B
C
F
B
C
D 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

8D–404 WIRING SYSTEM
STEP OPERATION ITEM TO BE CHECKEDITEM OF
REMARKS
MALFUNCTION
Activate alarm
device. Check to see if indicator light
goes off after about 10 seconds.
Check to see if alarm operates.
Check to see if alarm stops. Wait about 10 seconds.
Open engine hood with engine
hood release handle.
Insert key into starter switch and
turn it to “ACC” position.C
I
J 45
46
47
NOTE:When the connector of the anti–theft & keyless entry control unit is disconnected, the starter is inoperative.
In the checking of short wheel base model, Step Nos. 16 through 21 and Step Nos. 31 through 36 are omitted.

WIRING SYSTEM 8D–405
TERMINAL
CONNECTIONCHECK
OPERATIONCIRCUIT
NO. ITEM CONDITION
1 FRT door switch–LH, RH ContinuityOpen door Continuity
Close door No continuity
2 RR door switch–LH, RH ContinuityOpen door Continuity
Close door No continuity
3— — – –
4 Door lock key switch–LH, RH Continuity Lock with key Continuity
5 FRT door lock switch–LH, RH Continuity Lock Continuity
6 Tailgate switch ContinuityOpen tailgate Continuity
Close tailgate No continuity
8 Anti–theft horn Voltage – Approx. 12V
10 Battery Voltage – Approx. 12V
11 Door switch ContinuityUnlock with locking knob Continuity
Lock with locking knob No continuity
12 Engine hood switch ContinuityOpen engine hood Continuity
Close engine hood No continuity
13 Detect switch ContinuityUnlock with key Continuity
Lock with key No continuity
14 Door lock key switch Continuity Unlock Continuity
15 FRT door lock switch–LH, RH Continuity Unlock Continuity
16 Tamper switch Continuity – No continuity
17 Ground Continuity – Continuity
18 Starter switch Voltage Starter switch “ACC” Approx. 12V
19 Indicator light Voltage – Approx. 12V
20 Dome light Voltage Dome light “DOOR” position Approx. 12V
21 Anti-theft relay Voltage – Approx. 12V
22 Starter relay VoltageMode switch “P” or “N” Approx. 12V
Clutch pedal depressed Approx. 12V
Check the anti–theft & keyless entry control unit harness side connector B–20 by using a circuit tester.

METER AND GAUGE8E–9
Meter Assembly–Gasoline W/O TOD–2
Connector No. I–9
Te r m i n a lFunction
1A/T oil temp warning light
2Seat belt warning light
3Check trans warning light
4Brake warning light
5Check engine warning light
6Charge warning light
7Cigarette lighter illumination light
8Illumination controller
9Tachometer
10D position (A/T)
11—
12A/T shift indicator control unit
13—
142 position (A/T)
15Starter switch
16Cruise set indicator light
17Cruise main indicator light
184WD indicator light
19Ground (Gauge)
20—
21Winter drive indicator light
22Oil pressure warning light
23—
24Air bag warning light
25Power drive indicator light
26—
27—
28Turn signal indicator light (Left)
29—
30Ground
Connector No. I–10
Te r m i n a lFunction
1Turn signal indicator light (Right)
2L position (A/T)
3R position (A/T)
4Engine coolant temperature gauge
5Speedometer
6—
7—
8Battery (+)
9—
10Rear fog light
11P position (A/T)
12N position (A/T)
133 position (A/T)
14High-beam indicator light (–)
15High-beam indicator light (+)
16ABS indicator light
17—
18Fuel warning light
19Oil pressure gauge
20Fuel gauge
21—
22—

METER AND GAUGE8E–11
Meter Assembly–Gasoline W/TOD–2
Connector No. I–9
Te r m i n a lFunction
1—
2Air bag warning light
3A/T oil temp warning light
4Charge warning light
5Check engine warning light
6Check trans warning light
7Brake warning light
8—
9Tachometer
10—
11Turn signal indicator light (Left)
12A/T shift indicator control unit
132 position (A/T)
14D position (A/T)
15Rear (TOD)
16Auto (TOD)
17Check (TOD)
18Cruise set indicator light
19Cruise main indicator light
20Oil pressure warning light
21Front “1” (TOD)
22Front “2” (TOD)
23Front “3” (TOD)
24Cigarette lighter illumination light
25Illumination controller
26Starter switch
27—
28Winter drive indicator light
29Power drive indicator light
30—
Connector No. I–10
Te r m i n a lFunction
1Turn signal indicator light (Right)
2L position (A/T)
3R position (A/T)
4Check engine warning light
5Speedometer
6—
7—
8Battery (+)
9Engine coolant temperature gauge
10Ground
11P position (A/T)
12N position (A/T)
133 position (A/T)
14High beam indicator light (–)
15High beam indicator light (+)
16ABS indicator light
17—
18Fuel warning light
19—
20Fuel gauge
21Ground (Gauge)
22—

8F–1 BODY STRUCTURE
BODY AND ACCESSORIES
BODY STRUCTURE
CONTENTS
Service Precaution 8F–3. . . . . . . . . . . . . . . . . . . . . .
Frame 8F–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Description 8F–3. . . . . . . . . . . . . . . . . . . . . .
Frame Dimensions (L W B) 8F–4. . . . . . . . . . . . . . .
Frame Dimensions (S W B) 8F–5. . . . . . . . . . . . . . .
General Description 8F–6. . . . . . . . . . . . . . . . . . . . .
Front Bumper 8F–6. . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Location 8F–6. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Bumper Slider Bracket 8F–7. . . . . . . . . . . . . .
Removal 8F–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Bumper 8F–8. . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Location 8F–8. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–9. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Location (W/Rear Combination Light
and License Light) 8F–10. . . . . . . . . . . . . . . . . . . .
Removal 8F–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–11. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Location (W/Rear Combination Light) 8F–12
Removal 8F–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–13. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Bumper Slider 8F–14. . . . . . . . . . . . . . . . . . . . .
Removal 8F–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–14. . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Description 8F–15. . . . . . . . . . . . . . . . . . . . .
Cowl Cover 8F–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Location 8F–15. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–16. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Hood 8F–16. . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–16. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Bulge 8F–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Location 8F–17. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–17. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Hood Hinge 8F–18. . . . . . . . . . . . . . . . . . . . . .
Parts Location 8F–18. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–18. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Hood Lock 8F–19. . . . . . . . . . . . . . . . . . . . . . . Parts Location 8F–19. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–20. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radiator Grille And Front End Lower Panel 8F–20.
Parts Location 8F–20. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–21. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Fender Panel 8F–22. . . . . . . . . . . . . . . . . . . . . .
Parts Location 8F–22. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–23. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Body Mounting 8F–24. . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Location 8F–24. . . . . . . . . . . . . . . . . . . . . . . .
Removal (No.1 – No. 2) 8F–24. . . . . . . . . . . . . . . .
Removal (No. 3 — No. 6) 8F–25. . . . . . . . . . . . . . .
Installation 8F–26. . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Description 8F–27. . . . . . . . . . . . . . . . . . . . .
Body Dimension 8F–28. . . . . . . . . . . . . . . . . . . . . . . .
Instrument Panel Assembly 8F–48. . . . . . . . . . . . . . .
Parts Location 8F–48. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–49. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–53. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cross Beam Assembly 8F–54. . . . . . . . . . . . . . . . . . .
Parts Location 8F–54. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–54. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–55. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Door Assembly 8F–56. . . . . . . . . . . . . . . . . . . .
Parts Location 8F–56. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–56. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–56. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Door Assembly 8F–57. . . . . . . . . . . . . . . . . . . . .
Parts Location 8F–57. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–57. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–58. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Door Strikers 8F–58. . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustment 8F–58. . . . . . . . . . . . . . . . . . . . . . . . . . .
Door Check Arm Assembly (Front & Rear) 8F–59. .
Parts Location 8F–59. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–59. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8F–60. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Window Regulator, Glass And Glass
Run 8F–60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Location 8F–60. . . . . . . . . . . . . . . . . . . . . . . .
Removal 8F–60. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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 “wow–wows” 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.

4A2B–4DIFFERENTIAL (REAR 244mm)
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 “wow–wows” 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.