2004 DAEWOO LACETTI wheel

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 233
DAEWOO V–121 BL4
To engage the lock–up clutch, the direction of flow is modi-
fied (reversed) via a valve in the hydraulic selector unit. At
the same time, the space behind the lock–up clutch piston
is vented. The oil pressure passes from the turbine cham-
ber to the lock–up clutch piston and presses it against the
converter’s cover. The turbine is thus blocked by way of
the linings between the piston and cover, and permits rigid
through drive with no slip (or reduced slip if controlled) to
the mechanical stage of the transaxle.
Fluid Pump
The fluid pump is located between the torque converter
and the transaxle case and is driven directly by the torque
converter. The pump sucks the fluid through a filter and de-
livers it to the main pressure regulator valve of the control
system. Excess fluid flows back to the pump. The fluid
pump fulfills the following functions:
S Generates line pressure.
S Delivers fluid under pressure to the torque convert-
er, thus preventing air bubbles in the fluid.
S Induces a flow of fluid through the torque converter
in order to eliminate heat.
S Supplies fluid pressure to the hydraulic control sys-
tem.
S Supplies fluid pressure to the shift components.S Lubricates the transaxle with fluid.
Pump Housing
1. Disc
2. Shaft seal
3. Stator shaft
4. Pump wheel
5. Pump ring gear
6. Dowel pin
Planetary Gears
The ZF 4HP 16 automatic transaxle is equipped with a one
sun gear, 4 planetary gears, planetary carrier, ring gear.
Each gear is located one directly behind the other and are
linked together. In other words, front ring gear is perma-
nently linked to rear planet carrier, front planet carrier is
linked to rear ring gear.
The individual gear ratios are obtained by linking together
the gear set elements in different ways by means of
clutches and brakes.
On the 4HP 16, the power flow is directed into the plane-
tary gear set via rear planet carrier or rear sun gear, or via
both simultaneously, depending on the gear in question.
The output is always via the front planet carrier.

5A1 – 234IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Shift Elements: Multi–disc Clutches and
Brakes
The purpose of the shift elements is to perform shifts un-
der load without the tractive flow being interrupted.
The shift elements consist of the following.
1. Snap Ring
2. Steel Disc
3. Lined Disc
4. Cup Spring
5. Baffle Plate
6. Disc Carrier
7. Input Shaft
8. Oil Supply to Dynamic Pressure Equalizer
9. Oil Supply to Clutch
10. Cylinder
11. Piston
12. Spring Disc
The shift elements are engaged hydraulically. The pres-
surized oil reaches the space between the cylinder and
piston, as a result the discs are compressed. The clutch/
brake is engaged when the oil pressure drops, the cup
spring acting on the piston presses the piston back into its
initial position. The clutch/brake is now released again.
Depending on the gear, the multi–disc clutches B and E
supply the engine torque to the planetary gear train, with
multi–disc brakes C, D and F directing the torque into the
housing.The dynamic pressure at clutches B and E is equal : i.e.
the dynamic pressure in front of and behind the piston is
equal. This equalizing effect is achieved in the following
way.
The space between the baffle plate and piston is filled with
unpressurized oil. A dynamic pressure dependent on the
engine speed builds up. The space between pressure also
builds up. However, there is simultaneously a static pres-
sure, which causes the clutch to engage. If the static pres-
sure is relieved, the cup spring is able to force the piston
back into its original position.
The advantages of this dynamic pressure equalization
are:
S Reliable clutch opening in all speed ranges
S Smoother shifts.
Parking Lock
The parking lock is actuated via the selector lever when in
position P. It protects the vehicle mechanically against roll-
ing away.
The stop plate is actuated by the selector shaft, which is
permanently connected to the selector lever via a pull
cable. The parking lock pawl on the parking lock gear is
welded onto the lateral shaft of the transaxle and this pre-
vents the drive wheels from turning.
This blocks the driven wheels.
1. Pawl
2. Supporting Bolt
3. Leg Spring

5A2 – 28IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
FUNCTION CHECK
Confirm whether below condition before function check.
S Oil temperature is hot condition (50°C (122°F) ~
80°C (176°F)).
S Switch of A/C and light etc are off.
Stall Test
Stall test’ purpose is to inspect overall performance of A/T
and engine by measuring the stall speed in ”D” and ”R”
range.1. Chock 4 Wheels and apply parking brake fully, lock
vehicle perfectly.
2. Fully pressed on foot brake pedal with left foot.
3. Shift into ”D” and ”R” range, fully press on accelera-
tor pedal with right foot.
Quickly read stall speed at this time.
Standards
2390 ± 150 rpm
Notice : Do not continuously run longer than 5 sec be-
cause of extreme increasing oil temp.
Make sure to keep interval for more than 1 min between
stall tests.
Result of Stall Test
Cause of Failure
Lower than standards
both ”D” and ”R”Less engine power
Torque converter one way clutch failure
Higher than standards
only ”D”Lower line pressure
S Pressure control solenoid (PCS) failure
S Primary regulator valve failure
Forward clutch (C1) failure (Slipping)
No.2 One–way clutch (F2) failure
Higher than standards
only ”R”Lower line pressure
S Pressure control solenoid (PCS) failure
S Primary regulator valve failure
Reverse clutch (C3) failure (Slipping)
1st & reverse brake (B3) failure (Slipping)
Higher than standards
both ”D” and ”R”Lower line pressure
S Pressure control solenoid (PCS) failure
S Primary regulator valve failure
Oil pump failure
Oil strainer failure (clogging)
Oil leak for each range circuit
Time Lag Test
Time lag is time till slightly shock can be felt when shift le-
ver is shifted ”N”  ”D” and ”N”  ”R” while engine idling.
Time lag test can inspect hydraulic condition and clutch/
brake condition.
1. Chock 4 Wheels and apply parking brake fully, lock
vehicle perfectly.
2. Measure time lag by using stop watch from moment
when shift lever is shifted in ”N”  ”D” and ”N” 
”R” until moment slightly shock can be felt.”N  D”less than 0.7 sec
”N”  ”R”less than 1.2 sec
Notice : Make sure to take 3 measurement and take the
average value.
Make sure to keep interval for more than 1 min between
time lag tests. (That purpose is to remove clutch/brake
pressure was left unfinished.)

AISIN AUTOMATIC TRANSAXLE 5A2 – 29
DAEWOO V–121 BL4
Result of Time Lag TestCause of Failure
Longer than standards ”N”  ”D”Lower line pressure
S Pressure control solenoid (PCS) failure
S Primary regulator valve failure
Forward Clutch (C1) failure (Slipping)
Timing solenoid failure
Oil leak for ”D” range circuit
Longer than standards ”N”  ”R”Lower line pressure
S Pressure control solenoid (PCS) failure
S Primary regulator valve failure
Reverse clutch (C3) failure (slipping)
1st & reverse brake (B3) failure (slipping)
Oil leak for ”R” range circuit
Hydraulic Test
Hydraulic test can inspect working condition inside A/T by
measuring line pressure in ”D” / ”R” range and ”idle” / ”stall”
condition.
1. Chock 4 Wheels and apply parking brake fully, lock
vehicle perfectly.2. Install oil pressure gage adapter DW240–010–02 to
test hole for line pressure.
3. Fully pressed on foot brake pedal with left foot, shift
into ”D” and ”R” range and measure line pressure
”idle” / ”stall” condition.
Line pressure
Mpa (kgf/cm
2)
DR
Engine idle0.37 (3.9)
–0.14 (4.2)0.59 (6.0)
–0.68 (6.9)
Engine stall1.10 (11.3)
–1.23 (12.5)1.58 (16.2)
–1.83 (18.6)
Notice : Do not continuously run longer than 5 sec be-
cause of extreme increasing oil temp.
Make sure to keep interval for more than 1 min between
stall tests.
Make sure to check no oil leak after installing oil pressure
gage adapter.
Result of Hydraulic Test
Cause of Failure
Higher than standards
both ”D and ”R”Pressure control solenoid (PCS) failure
Primary regulator valve failure
Lower than standards
both ”D and ”R”Pressure control solenoid (PCS) failure
Primary regulator valve failure
Oil pump failure
Oil strainer failure (clogging)
Oil leak for each range circuit
Lower than standards
only ”D”D” hydraulic circuit failure
Forward clutch (C1) failure
Lower than standards
only ”R””R” hydraulic circuit failure
Reverse clutch (C3) failure
1st and reverse brake (B3) failure

5A2 – 60IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DTC P0722 Output Shaft Speed (OSS) sensor Circuit No Signal
StepActionValue(s)YesNo
11. Turn the ignition OFF.
2. Install the Scan tool.
3. With the engine OFF, turn the ignition switch to
the ON position.
4. Select Store Freeze Frame/Failure Records
from the Diagnostic Trouble Codes Information
menu.
5. Store Freeze Frame/Failure Records.
6. Select Clear DTC Information from the Diag-
nostic Trouble Codes Information menu.
7. Clear DTC Information.
8. Perform one vehicle drive cycle.
Is the Malfunction Indicator Lamp (MIL) ON?–Go to Step 2Repair the tem-
porary connec-
tion failure of
connector (Re-
fer to ”Wiring
Harness and
Connector In-
spection” in this
section.)
21. Select Request DTC by Status from the Diag-
nostic Trouble Codes Information menu.
2. Request DTC by Status.
Is DTC P0722 displayed?–Go to Step 3Repair the tem-
porary connec-
tion failure of
connector (Re-
fer to ”Wiring
Harness and
Connector In-
spection” in this
section.)
31. Turn the ignition OFF.
2. Inspect the voltage between vehicle harness
and the Output Shaft Speed (OSS) sensor.
3. Disconnect the connector (X–1) of the vehicle
harness.
4. Connect the voltmeter to monitor the voltage
between terminal B25 and ground.
5. Turn ignition ON and lift up the vehicle.
6. Check the voltage change from approximately
0 v to 12 v when the wheel is turned slowly.
Does the measurement change within the specified
value?0–12 vGo to Step 4Go to Step 5
41. Estimate the failure of between the vehicle wir-
ing harness connector and TCM.
2. Inspect the connector. Refer to ”Wiring Har-
ness and Connector Inspection” in this section.
3. Inspect the connection condition between the
connectors (C–1).
Is the connection condition OK?–Go to Step 6Repair the wir-
ing harness
connectors.
51. Estimate the failure of T/M wire or between the
connectors of OSS sensor.
2. Inspect the OSS sensor. Refer to ”Unit Inspec-
tion” in this section
Is the condition of OSS sensor OK?–Go to Step 7Replace the
OSS sensor

5B – 2IFIVE–SPEED MANUAL TRANSAXLE
DAEWOO V–121 BL4
SPECIFICATIONS
FASTENER TIGHTENING SPECIFICATIONS
ApplicationNSmLb–FtLb–In
Backup Lamp Switch2015–
Bearing Plate Bolts2216–
Bearing Retainer Bolts, Right Side2518–
Bearing–Adjusting Ring–Retainer Plate Bolt5–44
Clutch–Release Cylinder Retaining Bolts2015–
Damping Block Connection Nut and Bolt6850–
Differential Cover Bolts4030–
Fifth–Gear Fork Bolts2216–
Fifth–Gearshift Connector Bolts7–62
Flywheel Inspection Cover Bolts7–62
Gearshift Housing Bolts7–62
Gearshift Lever Cover Bolts2216–
Input Driveshaft Detent Screw1511–
Rear Damping Block Retaining Bolts6850–
Rear Mounting Bracket Bolts9066–
Ring–Gear Bolts7052–
Rod Clamp Bolt14–124
Speedometer Housing Retaining Bolt4–35
Speedometer–Driven Gear Bolt5–44
Transaxle Cover Bolts1813–
Transaxle Lower Retaining Bolts(a)7354–
Transaxle Lower Retaining Bolt(b)3123–
Transaxle Lower Retaining Bolts(c)2115–
Transaxle Upper Retaining Bolts7354–
Transaxle Upper Mounting Bracket Bolts4835–

FIVE–SPEED MANUAL TRANSAXLE 5B – 5
DAEWOO V–121 BL4
DIAGNOSIS
ISOLATE NOISE
Identify the cause of any noise before attempting to repair
the clutch, the transaxle, or their related link–ages.
Symptoms of trouble with the clutch or the manual trans-
axle include:
S A great effort required to shift gears.
S The sound of gears clashing and grinding.
S Gear blockout.
Any of these conditions requires a careful analysis. Make
the following checks before disassembling the clutch or
the transaxle for repairs.
Road Travel Noise
Many noises that appear to come from the transaxle may
actually originate with other sources such as the:
S Tires.
S Road surfaces.
S Wheel bearings.
S Engine.
S Exhaust system.
These noises may vary according to the:
S Size of the vehicle.
S Type of the vehicle.
S Amount of insulation used in the body of the ve-
hicle.
Transaxle Noise
Transaxle gears, like any mechanical device, are not ab-
solutely quiet and will make some noise during normal op-
eration.
To verify suspected transaxle noises:
1. Select a smooth, level asphalt road to reduce tire
and resonant body noise.
2. Drive the vehicle far enough to warm up all the lu-
bricants thoroughly.
3. Record the speed and the gear range of the trans-
axle when the noise occurs.
4. Check for noises with the vehicle stopped, but with
the engine running.
5. Determine if the noise occurs while the vehicle op-
erates in:
S Drive – under a light acceleration or a heavy
pull.
S Float – maintaining a constant speed with a light
throttle on a level road.
S Coast – with the transaxle in gear and the
throttle partly or fully closed.
S All of the above.
Bearing Noise
Differential Side Bearing Noise
Differential side bearing noise and wheel bearing noise
can be confused easily. Since side bearings are pre–
loaded, a differential side bearing noise should not dimin-
ish much when the differential/transaxle is run with the
wheels off the ground.
Wheel Bearing Noise
Wheel bearings produce a rough growl or grating sound
that will continue when the vehicle is coasting and the
transaxle is in NEUTRAL. Since wheel bearings are not
pre–loaded, a wheel bearing noise should diminish con-
siderably when the wheels are off the ground.
Other Noise
Brinelling
A brinelled bearing causes a ”knock” or ”click” approxi-
mately every second revolution of the wheel because the
bearing rollers do not travel at the same speed as the
wheel. In operation, the effect is characterized by a low–
pitched noise.
A brinelled bearing is caused by excessive thrust which
pushes the balls up on the pathway and creates a triangu-
lar–shaped spot in the bearing race. A brinelled bearing
can also be caused from pressing one race into position
by applying pressure on the other race.
A false indication of a brinelled bearing occurs as a result
of vibration near the area where the bearing is mounted.
Brinelling is identified by slight indentations, resulting in a
washboard effect in the bearing race.
Lapping
Lapped bearing noise occurs when fine particles of abra-
sive materials such as scale, sand, or emery circulate
through the oil in the vehicle, causing the surfaces of the
roller and the race to wear away. Bearings that wear loose
but remain smooth, without spalling or pitting, are the re-
sult of dirty oil.
Locking
Large particles of foreign material wedged between the
roller and the race usually causes one of the races to turn,
creating noise from a locked bearing. Pre–loading regular
taper roller bearings to a value higher than that specified
also can result in locked bearings
Pitting
Pitting on the rolling surface comes from normal wear and
the introduction of foreign materials.
Spalling
Spalled bearings have flaked or pitted rollers or races
caused by an overload or an incorrect assembly that re-
sults in a misalignment, a cocking of bearings, or adjust-
ments that are too tight.
After completing these checks, refer to the ”Diagnosis
Chart” in this section.

5B – 6IFIVE–SPEED MANUAL TRANSAXLE
DAEWOO V–121 BL4
SYMPTOM DIAGNOSIS
ChecksAction
Check for a knock at low speeds.S Replace any worn drive axle CV joints.
S Replace any worn side gear hub.
Check for a noise most pronounced on turns.S Correct any abnormalities in the differential gear.
Check for a clunk upon acceleration or deceleration.S Tighten any loose engine mounts.
S Replace any worn drive axle inboard joints.
S Replace any worn differential pinion shaft in the
case.
S Replace any worn side gear hub in the case.
Check for a clunking noise in turns.S Replace any worn outboard CV joint.
Check for a vibration.S Replace any rough wheel bearing.
S Replace any bent drive axle shaft.
S Replace any out–of–round tires.
S Balance any unbalanced tire.
S Replace any worn CV joint in the drive axle shaft.
S Correct an excessive drive axle angle by adjusting
the trim height.
Check for a noise in the NEUTRAL gear with the engine
running.S Replace any worn cluster bearing shaft.
S Replace any worn clutch–release bearing.
S Replace any worn input shaft cluster gears.
S Replace any worn first–gear/bearing.
S Replace any worn second–gear/bearing.
S Replace any worn third–gear/bearing.
S Replace any worn fourth–gear/bearing.
S Replace any worn fifth–gear/bearing.
S Replace any worn mainshaft bearings.
Check for a noise in the first gear (1) only.S Replace any chipped, scored, or worn first–gear
constant mesh gears.
S Replace any worn first–second gear synchronizer.
S Replace any worn first–gear/bearing.
S Replace any worn differential–gear/bearing.
S Replace any worn–ring gear.
S Adjust, repair, or replace the shift lever and the rods.
Check for a noise in the second gear (2) only.S Replace any chipped, scored, or worn second–gear
constant mesh gears.
S Replace any worn first–second gear synchronizer.
S Replace any worn second–gear/bearing.
S Replace any worn differential–gear/bearing.
S Replace any worn–ring gear.
S Adjust, repair, or replace the shift lever and the rods.
Check for a noise in the third gear (3) only.S Replace any chipped, scored, or worn third–gear
constant mesh gears.
S Replace any worn third–fourth gear synchronizer.
S Replace any worn third–gear/bearing.
S Replace any worn differential–gear/bearing.
S Replace any worn–ring gear.
S Adjust, repair, or replace the shift lever and the rods.