ect LEXUS SC300 1991 Service Repair Manual

GENERAL DESCRIPTION
SR0E7±02

Care must be taken to replace parts properly because they could affect the p\
erformance of the steering
system and result in a driving hazard.

The steering wheel pad has an airbag built in, so take all due precautio\
ns when handling it. For more
details, see the RS section.
TROUBLESHOOTING
SR0E8±02
You will find the cause of trouble more easily by properly using the table \
shown below. In this table, the
numbers indicate the priority of the probable cause of trouble. Check each part in the order shown. If neces-
sary, repair or replace the part.
SA±3
SR±113SA±41
SR±167
SR±163
SA±16SA±3
SR±2±
STEERING GENERAL DESCRIPTION, TROUBLESHOOTING
WhereEverybodyKnowsYourName

ON±VEHICLE INSPECTION
SR0E9±02
CHECK THAT STEERING WHEEL FREEPLAY IS COR-
RECT
With the vehicle stopped and tires pointed straight ahead,
rock the steering wheel gently back and forth with light finger
pressure.
Freeplay should not exceed the maximum.
Maximum freeplay:30 mm (1.18 in.)
If incorrect, repair.
±
STEERING ON±VEHICLE INSPECTIONSR±3
WhereEverybodyKnowsYourName

POWER TELESCOPIC OPERATION
SR0EC±02
The power telescopic mechanism is composed of the control gear assembly, telescopic motor, telescopic
position sensor, tilt and telescopic switch, unlock warning switch and tilt and telesco\
pic ECU.
The control gear assembly is composed of the worm wheel, telescopic scre\
w and slider. Rotation of the
telescopic motor moves the slider in the direction of the telescopic screw axis. The\
sliding tube is integrated
with the slider and is moved forward and backward by movement of the slider.
±
STEERING STEERING COLUMNSR±5
WhereEverybodyKnowsYourName

MAIN POINTS OF REMOVAL AND
INSTALLATION
NOTICE:
wIf the SRS (Supplemental Restraint System) connector is
disconnected with the ignition switch at ON or ACC,
diagnostic trouble codes will be recorded.
w Never use SRS parts from another vehicle. When
replacing parts, replace with new parts.
1. DISCONNECT NEGATIVE (±) TERMINAL CABLE FROM
BATTERY
CAUTION: W ork must be started after 90 seconds from the time
the ignition switch is turned to the ªLOCKº position and the
negative (±) terminal cable is disconnected from the battery.
(See RS section)
2. REMOVE STEERING WHEEL PAD
(a) Place the front wheels facing straight ahead.
(b) Remove the No.2 and No.3 covers.
(c) Using a torx wrench, loosen the 4 torx screws. Torx wrench: T30 (Part No. 09042±00010 or locally manufac-
tured tool)
HINT: Loosen the 4 screws until the groove along the screw
circumference catches on the screw case.
(d) P u l l t h e w heel pad out from the steering wheel and
disconnect the Airbag connector.
NOTICE: When removing the wheel pad, take care not to pull
the Airbag wire harness.
CAUTION:
w When storing the wheel pad, keep the upper surface of
the pad facing upward.
w Never disassemble the wheel pad.
3. REMOVE STEERING WHEEL
(a) Disconnect the connector.
(b) Remove the steering wheel set nut.
(c) Place matchmarks on the steering wheel and main shaft.
(d) Using SST, remove the wheel.
SC400:
SST 09213±31021
SC300:
SST 09609±20011
SR±10
±
STEERING STEERING COLUMN
WhereEverybodyKnowsYourName

4. CENTER SPIRAL CABLE
(a) Check that the front wheels are facing straight ahead.
(b) Turn the spiral cable counterclockwise by hand until it
becomes harder to turn the cable.
(c) Then rotate the spiral cable clockwise about 3 turns to align the red mark.
HINT: The spiral cable will rotate about 3 turns to either left
or right of the center.
5. INSTALL STEERING WHEEL
(a) Align matchmarks on the steering wheel and main shaft, and install the wheel to the shaft.
(b) Tighten the wheel set nut.
Torque: 35 N Vm (360 kgf Vcm, 26 ft Vlbf)
(c) Connect the connector.
6. INSTALL STEERING WHEEL PAD
(a) Connect the Airbag connector.
(b) Install the pad after confirming that the circumference groove
of the torx screws is caught on the screw case.
(c) Using a torx wrench, tighten the 4 torx screws.
Torque: 7.4 N Vm (75 kgf Vcm, 65 in. Vlbf)
NOTICE:
w Make sure the wheel pad is installed to the specified
torque.
w If the wheel pad has been dropped, or there are cracks,
dents or other defects in the case or connector, replace
the wheel pad with a new one.
w When installing the wheel pad, take care that the wiring
does not interfere with other parts and is not pinched
between other parts.
7. CHECK STEERING WHEEL CENTER POINT
8. CONNECT NEGATIVE (±) TERMINAL CABLE TO
BATTERY
±
STEERING STEERING COLUMNSR±11
WhereEverybodyKnowsYourName

SECTIONAL VIEW
SR0EQ±02
±
STEERING STEERING COLUMNSR±13
WhereEverybodyKnowsYourName

5. REMOVE TURN SIGNAL BRACKET
6. REMOVE PROTECTOR
7. REMOVE CONNECTOR BRACKET
8. REMOVE TELESCOPIC LEVER SERRATIONATTACHMENT
Remove the nut and the serration attachment.
9. REMOVE TELESCOPIC LEVER
(a) Remove the bolt, collar, lever and washer.
(b) Remove the ball and compression spring.
±
STEERING STEERING COLUMNSR±15
WhereEverybodyKnowsYourName

(b) Remove the main shaft from the column tube.
(c) Remove the spring, thrust collar and bearing.
STEERING COLUMN INSPECTION AND
REPLACEMENT
SR0ES±03
1. INSPECT KEY CYLINDERCheck that the steering lock mechanism operates properly.
2. IF NECESSARY, REPLACE KEY CYLINDER
(a) Place the ignition key at the ACC position.
(b) Push down the stop pin with a thin rod, and pull out the key cylinder.
(c) Install a new key cylinder. HINT: Make sure the ignition key is at the ACC position.
3. INSPECT UPPER BEARING Check the upper bearing rotation condition and check for ab-
normal noise.
If the bearing is worn or damaged, replace the column upper
tube.
STEERING COLUMN ASSEMBLY
SR0ET±04
1. APPLY MOLYBDENUM DISULPHIDE LITHIUM BASEGREASE (See page SR±12)
2. INSTALL MAIN SHAFT
(a) Install the bearing, thrust collar and spring to the main shaft.
(b) Install the main shaft into the upper column tube.
±
STEERING STEERING COLUMNSR±19
WhereEverybodyKnowsYourName

(c) Using SST to compress the compression spring.SST 09950±20017 (09956±00010)
(d) Using snap ring pliers, install a new snap ring.
3. INSTALL TILT MEMORY BOLT
(a) Install the square nut and tilt memory bolt.
(b) Using a hexagon wrench, torque the tilt memory bolt.
Torque: 6.4 N Vm (65 kgf Vcm, 56 in. Vlbf)
4. SELECT TILT STEERING BOLTS
Select the bolt with the plain thread end when the upper col-
umn tube mark is 2, and the bolt with the hollow±tipped
thread end when the mark is 1.
5. INSTALL MAIN SHAFT WITH UPPER COLUMN TUBE
(a) Install the main shaft with the upper column tube into the lower column tube.
(b) Using a vise, press in the 2 tilt steering bolts. HINT: Make sure the upper tube turns smoothly.
SR±20
±
STEERING STEERING COLUMN
WhereEverybodyKnowsYourName

9. SELECT 2 PAWL STOPPERS
(a) With the tilt pawl and ratchet engaged, install the 2 pawlstoppers.
(b) Check that the alignment marks on the stopper and pawl
align when the stopper is lightly rotated to the pawl side.
(c) If the alignment marks do not align, select pawl stoppers according to the following table.
 

Tilt lever side
 

Tilt sub lever side
 

Dimension ªAº
mm (in.)
 

1
 

A
 

12.68 ± 12.74
(0.4992 ± 0.5016)
 

2
 

B
 

12.61±12.67
(0.4965 ± 0.4988)
 

3
 

C
 

12.54 ± 12.60
(0.4937 ± 0.4961)
 

4
 

D
 

12.47 ± 12.53
(0.4909± 0.4933)
 

5
 

E
 

12.40 ± 12.46
(0.4882 ± 0.4906)
 

6
 

F
 

12.33 ± 12.39
(0.4854 ± 0.4878)
 

7
 

G
 

12.26 ± 12.32
(0.4827 ± 0.4850)
(d) After selecting the stoppers, check that on both sides the
pawl and ratchet are fully engaged.
10. I N S TA L L 2 PAW L S TO PPERS AND 2 TILT LEVER
RETAINERS
(a) Install the tilt sub lever side pawl stopper and retainer.
(b) Install the spacer and new E±ring.
(c) Install the nut to the tilt steering bolt.
Torque: 15 N Vm (150 kgf Vcm, 11 ft Vlbf)
(d) Install the collar to the tilt memory bolt.
(e) Install the nut to the tilt memory bolt.
Torque: 5.9 N Vm (60 kgf Vcm, 52 in. Vlbf)
(f) Install the tilt lever side pawl stopper and tilt lever retainer.
(g) Install the E±ring.
(h) Install and torque the nut.
Torque: 15 N Vm (150 kgf Vcm, 11 ft Vlbf)
SR±22±
STEERING STEERING COLUMN
WhereEverybodyKnowsYourName