1988 PONTIAC FIERO towing

OB-2 MAINTENANCE AND LUBRICATION
Select and follow Schedule I or Schedule I1 based on how you use your car:
SCHEDULE I
Follow Schedule I if your car is mainly operated under one or moreof the following Idling andlor low
speed operation in stop-and-go traffic.
conditions: Towing a trailer.
@ When most trips are less than 4 miles (6 kilometers).
Operating in dusty areas.
When most trips are less than 10 miles (16 kilometers) and outside temperatures
Schedule I should also be followed if the car is used for delivery service,
remain below freezing.
police, taxi or other commercial applications.
TO BE SERVICED
Every
30.000 miles I50 000 km)
Every 30,000 miles I50 000 km) or 36 months
Every
30,000 miles 150 000 km)
SCHEDULE ll
Follow Schedule II only if none of the driving conditions specified in Schedule I apply.
TO BE SERVICED
At
7 500 miles 12 500 km on1
FOOTNOTES:
I
*An Emission Control Service ttThe U.S. Environmental Protection Agency has determined that the failure to perform this
maintenance item will not nullifv the emission warrantv or limit recall liabilitv orior to the
completion of vehicle useful life. General Motors, however, urges that all recommended main-
tenance services be performed at the indicated intervals and the maintenance be recorded in
section C of the owner's
ma~ntenance schedule.
Figure OB-1 Maintenance Schedules I and I1 - Gasoline Vehicles

700-R4-2 HYDRAULIC DIAGNOSIS
R - Reverse allows the vehicle to be operated in
a rearward direction.
N - Neutral allows the engine to be started and
operated without driving the vehicle. If necessary this
position may be selected if the engine must be restarted
with the vehicle moving.
D - Overdrive is used for all normal driving
conditions. It provides four gear ratios plus converter
clutch operation. Downshifts are available for safe
passing by depressing the accelerator.
D - Drive position is used for city traffic, hilly
terrain, and trailer towing. It provides three gear
ranges. Again, downshifts are available by depressing
the accelerator.
2 - Manual second is used to provide acceleration
and engine braking. This range may be selected at any
vehicle speed.
1 - Manual Lo is used to provide maximum
engine
brlking. This range may also be selected at any
vehicle speed.
DIAGNOSIS INFORMATION
ROAD TEST PROCEDURE
e Perform the road test following the sequence
given
e MPH (KPH) shift points will vary with actual
throttle position and driver habits
e Compare the results of the test with speed shift
chart information. Use these results with the
diagnosis information contained in this
Automatic Transmission Hydraulic Diagnosis
Section to evaluate the transmission.
e This test should only be performed when traffic
and road conditions permit
e Observe all traffic safety regulations
Drive and Reverse Engagement Shift Check
1. Start engine
2. Depress brake pedal
3. Move gear selector:
- "Park" (P) to "Reverse" (R)
- "Reverse" (R) to "Neutral"
(N) to "Drive" (D)
Gear selections should be immediate and
not harsh.
Upshifts and Torque Converter Clutch (TCC)
Apply (Figure
2)
With gear selector in "Overdrive" (D)
1. Accelerate using a steady increasing throttle
pressure
2. Note the shift speed point gear engagements for:
- 2nd gear
- 3rd gear
- Overdrive
3. Note the speed shift point for TCC apply. This
should occur while in third gear or overdrive. If
the apply is not noticed, refer to the Preliminary
Torque Converter Clutch Diagnosis information
contained in this section of the Service Manual.
Important
The torque converter clutch will not engage if
engine coolant has not reached a minimum
operating temperature of approximately 54°C
(1 30°F).
Part Throttle Downshift
At vehicle speeds of 40-55 MPH (64-88
KPH) quickly depressed the accelerator to
a half open position and observe:
- TCC releases
- Transmission downshift to 3rd gear
immediately
Full Throttle (Detent) Downshift
At vehicle speeds of 48-55 MPH (77-88
KPH) quickly depress the accelerator to a
wide open position and observe:
- TCC releases
- Transmission downshifts to 2nd gear
immediately
Manual Downshift
1. At vehicle speeds of 40-55 MPH (64 to 88 KPH)
release the accelerator pedal while moving the
gear selector to "Third" gear (D) and observe:
- TCC release
- Transmission downshift to 3rd gear should
be immediate
- Engine should slow vehicle down
2. Move gear selector to "Overdrive" and accelerate
to 40-45 MPH (64-72 KPH). Release the
accelerator pedal while moving the gear selector
to "Second" gear (2) and observe.
- TCC release
- Downshift to second gear should be
immediate
- Engine should slow vehicle down
3. Move gear selector to "Overdrive" (D) and
accelerate to 25 MPH (40 KPH). Release the
accelerator pedal while moving the gear selector
to "First" gear (1) and observe:
- TCC release
- Transmission downshift to 1st gear should
be immediate
- Engine should slow vehicle down
Coastdown Downshift
1. With the gear selector in "Overdrive" (D)
accelerate to 4th gear with TCC applied.
2. Release the accelerator pedal and lightly apply
the brakes to observe:
- TCC release
- Shift points for downshifts.
Manual Gear Range Selection
MANUAL THIRD (D)
1. With vehicle stopped, place gear selector in
"Third" (D) and accelerate to observe:

7A-2 AUTOMATIC TRANSMISSION
I I
M - INDICATES TRANSMISSION
TYPE IN OPTION LIST. (SPECIFIC MODEL CODE IS FOUND ON THE I MX - DESIGNATES
11 SERVICE PARTS IDEMTIFICATIOM I 1 00 MOT REMOVE I
1G3AR47YXE5
C90 C95 DF3 D3C 033 0 GI GW9 G60 GU2 G89
JAl JA4 KO5 K22 Kg9 LV2 NA5 NB1 NKl NK3 N33 N67 GJW
T87 UJ3 U23 U35
VO8 V10 WC3 WG2 YT9 Y56 OIL 6SC 428 421 420
Figure 2 Service Parts ldentificaiton Label
TRANSMISSION DEFINITIONS
The following definitions are being provided to
establish a common language and assist the user in
describing transmission related conditions. Some of
these terms or conditions are used in the transmission
sections of this Service Manual.
Throttle Positions
Minimum Throttle - the least amount of
throttle opening required for an upshift.
Light Throttle - approximately 1/4 of
accelerator pedal travel.
Medium Throttle - approximately 1/2 of
accelerator pedal travel.
Heavy Throttle - approximately 3/4 of the
accelerator pedal travel.
Wide Open Throttle (WOT) - full travel of
the accelerator pedal.
Full Throttle Detent Downshift - a quick
apply of the accelerator pedal to its full travel,
forcing a downshift.
Zero Throttle Coastdown - a full release of
the accelerator pedal while the vehicle is in
motion and in drive range.
Engine Braking - a condition where the engine
is used to slow the vehicle by manually
downshifting during a zero throttle coastdown.
Shift Conditions
'a Bump - a sudden and forceful apply of a clutch
or band.
Q Chuggle - a bucking or jerking condition that
may be engine related. May be most noticeable
when the converter clutch is engaged. Similar to
the feel of towing a trailer.
e Delayed - a condition where a shift is expected
but does not occur for a period of time. Samples
of this condition could be described as clutch or
band engagement does not occur as quickly as
expected during a part throttle or wide open
throttle apply of the accelerator or, when
manually downshifting to a lower range. Also
defined as "LATE" or, "EXTENDED."
Double Bump ("Double Feel") - two sudden
and forceful applies of a clutch or band.
Early - a condition where the shift occurs before
the vehicle has reached a proper speed and tends
to labor the engine after the upshift.
End Bump - a firmer feel at the end of a shift as
compared to the feel at the start of the shift. Also
defined as "END FEEL" or, "SLIP BUMP."
Firm - a noticeable quick apply of a clutch or
band that is considered
normal with a medium
to heavy throttle shift. Should not be confused
with "HARSH" or "ROUGH."
Flare - a quick increase in engine rpm
accompanied with a momentary loss of torque.
This most generally occurs during a shift. Also
defined as "SLIPPING.
"
Harsh ("Rough") - a more noticeable apply of
a clutch or band as compared to "FIRM." This
condition is considered undesireable at any
throttle position.
Hunting - a repeating quick series of upshifts
and downshifts that causes a noticeable change in
engine rpm. An example could be described as a
4-3-4 shift pattern. Also defined as
"BUSYNESS.
"
Initial Feel - a distinct firmer feel at that start
of a shift as compared to the finish of the shift.
Late - a shift that occurs when the engine is at
a higher than normal rpm for a given amount of
throttle.
Shudder - a repeating jerking sensation similar
to "CHUGGLE" but more severe and rapid in
nature. This condition may be most noticeable
during certain ranges of vehicle speed. May also
be used to define the condition after converter
clutch engagement.
Slipping - a noticeable increase in engine rpm
without a vehicle speed increase.
A slip usually
occurs during or after initial clutch or band
engagement.
Soft - a slow, almost unnoticeable clutch apply
with very little shift feel.
Surge - a repeating engine related feeling of
acceleration and deceleration that is less intense
than "CHUGGLE.
"
Tie-Up - a condition where two opposing
clutches are attempting to apply at the same time
causing the engine to labor with a noticeable loss
of engine rpm.
,e Conditions
Gear Noise - a whine, most noticeable in first
gear and reverse that is related to vehicle speed.
A gear noise condition may become less
noticeable or go away after an upshift.
Pump Noise - a high pitch whine that increases
in intensity with engine
rpm. This condition may
also be noticeable in
"PARK" and "NEUTRAL"
operating ranges with the vehicle stationary.

AUTOMATIC TRANSMISSION 7A-3
PRELIMARY CHECKING PROCEDURE
The condition of an automatic transmission not
operating properly may be influenced by one, or a
combination of the following items:
e Fluid level high/low
(Refer to Section 7A1)
e Engine performance
(Refer to Sections 6 and 6E)
T.V. cable adjustment
(Refer to Section
7A1)
e Manual linkage adjustment
(Refer to Section
7A1)
e Internal fluid leaks
(Refer to Transmission Unit Repair section)
e Electrical system
(Refer to Section 6E and 8A)
e Transmission or other mechanical component
(Refer to Transmission Unit Repair section)
e Vacuum modulator
(Refer to appropriate Hydraulic Diagnosis
Section)
NOISE AND VIBRATION ANALYSIS
A noise or vibration that is noticeable when the
vehicle is in motion, MAY NOT be the result of the
transmission.
If noise or vibration is noticeable in "Park"
(P)
and "Neutral" (N) with engine at idle, but is less
noticeable as
RPM's increase, the cause may be from
poor engine performance.
e Tires for
- Uneven wear
- Imbalance
- Mixed sizes
- Mixed radial and bias ply
(Refer to Section 3E)
e Suspension components for
- Alignment and wear
- Loose fasteners
(Refer to Section 3C)
e Engine/Transmission mounts for
- Damage
- Loose bolts
(Refer
to Sections 6A and 7A2)
e Transmission case mounting holes for:
- Missing bolts, nuts, studs
- Stripped threads
- Cracks
e Flywheel for:
- Missing or loose bolts
- Cracks
- Imbalance
(Refer to Section 6A)
e Torque converter for: - Missing or loose bolts or lugs - Missing or loose balance weights
- Imbalance
TRANSMISSION FLUID LEVEL INFORMATION
Checking fluid level, color and condition at
regular intervals will provide early diagnosis
information about the transmission. This information
may then be used to correct a condition that, if not
detected early, could result in major transmission
repairs.
When adding or changing fluid, use only
DEXRONO 11, or equivalent. Refer to Section OB of
this Service Manual for maintenance information and
servicing intervals.
Fluid level should be checked when it reaches
normal operating temperatures of
190-200°F.
(88-93°C). This temperature is reached after
approximately 15 miles (24 km) of highway
driving.
e Fluid color - Should be dark red (may be dark green)
NOTICE: Do not overfill. Overfilling will cause
foaming, loss of fluid and possible damage to the
transmission.
Inaccurate fluid level readings will result if
checked immediately after the vehicle has been
operated:
- In high abmient temperatures above 90°F
(32°C)
- At sustained high speeds
- In heavy city traffic during hot weather
- As a towing vehicle - In commercial service (taxi or police use)
TRANSMISSION FLUID CHECKING
PROCEDURE
(Refer to Figure 3)
1. Park vehicle on level ground.
2. Apply parking
brake and block wheels.
3. Start
engine and operate vehicle for 15 minutes or
until a normal operating temperature is reached.
4. Move gear
selector through all gear positions.
5. Move
gear selector to "Park" (P).
6. Check fluid level, color and condition.