Canada - Steering - Notchy Steering Feel At Highway Speed
BulletinL-TCI-2967
Issue Date
August 31, 2011
Title:
NOTCHY STEERING FEEL AT HIGHWAY SPEEDS (4WD)
Service Category
Steering
Section
Steering Gear/Linkage
Market
Canada
Applicability
Introduction
Some Lexus vehicles may exhibit an intermittent non-binding, notchy steering feeling and/or the steering wheel does not smoothly self-center when driving at highway speeds. This condition may occur when changing lanes or when coming out of long sweeping turns at highway speeds. Please use the following repair procedure to address this condition.
Production Change Information
This TSB applies to all 2006 model year GS300 vehicles, and to vehicles produced BEFORE the Production Change Effective VINs shown.
Parts Information
Warranty Information
Required Tools & Equipment
Repair Procedure
1. Conduct a road test to verify the steering feel condition.
Did the steering exhibit a condition of an intermittent non-binding, notchy steering feeling and/or steering wheel not smoothly self-centering when driving at highway speeds?
- YES - This TSB DOES apply.
Go to Step 2 for power steering gear assembly replacement.
- NO - This TSB does NOT apply. Refer to the applicable Repair Manual for diagnosis.
2. Secure the front wheels in a straight ahead position.
A. Place the front wheels in a straight-ahead position and center the steering wheel.
B. Center and secure the steering wheel. This will prevent the steering wheel from rotating and damaging the spiral cable.
3. Disconnect the negative battery cable.
CAUTION
- DO NOT disconnect the negative (-) battery cable until 6 minutes have elapsed after turning the ignition OFF. This allows the HDD navigation system to save memory and settings.
- Work must be started at least 90 seconds after the engine switch is turned off and after the cable is disconnected from the negative (-) battery terminal. The SRS is equipped with a back-up power source. If work is started within 90 seconds after turning the engine switch off and disconnecting the cable from the negative (-) battery terminal, the SRS may deploy.
4. Remove the front wheels.
5. Remove the engine under covers.
6. Remove the cool air intake duct seal.
7. Remove the engine room front and side covers.
8. Loosen the front shock absorber assembly.
A. Loosen the three front shock absorber assembly nuts, but Do Not remove.
B. Repeat the procedure on the opposite side.
9. Disconnect the wheel speed sensor wire.
A. Disconnect the connector.
B. Remove the three bolts.
C. Repeat the procedure on the opposite side.
10. Separate the front height control sensor link sub-assembly.
A. Remove the nut and separate the height control sensor link.
B. Repeat the procedure on the opposite side.
11. Separate the front lower ball joint assembly.
A. Remove the two bolts and separate the front lower ball joint assembly
B. Repeat the procedure on the opposite side.
12. Separate the tie rod assembly.
A. Remove the clip and nut.
NOTICE
Dispose of OLD clip as it is a non-reusable part.
B. Repeat the procedure on the opposite side.
C. Using SST 09628-00011, separate the tie rod from the steering knuckle.
D. Repeat the procedure on the opposite side.
NOTICE
- Hang the SST with the tether to prevent it from falling.
- DO NOT damage the disc brake dust cover.
- DO NOT damage the ball joint dust boot.
- DO NOT damage the steering knuckle.
13. Separate the front stabilizer link assembly.
A. Remove the nut and separate the front stabilizer link assembly.
B. Repeat the procedure on the opposite side.
14. Remove the front shock absorber bracket.
A. Remove the nut and plate.
B. Remove the bolt and remove front shock absorber bracket.
C. Repeat the procedure on the opposite side.
15. Separate the steering intermediate shaft assembly No. 2.
A. Remove the bolt.
B. Separate the steering intermediate shaft assembly No. 2.
16. Remove power steering link assembly.
A. Remove bolt (A) and the power steering ground wire from the power steering link assembly.
B. Remove bolt (B) to disconnect the ground wire from the bracket.
C. Remove bolt (C) and the bracket.
D. Disconnect two connectors (D) and (E) from the power steering link assembly.
E. Unlock and raise the lock for connector (F) as illustrated, and disconnect the wire harness.
F. Remove the two bolts and nuts for the EPS assembly.
G. Using a screw jack or another similar device, support the rear of the vehicle at the rear differential.
H. Position two blocks of wood as shown in the illustration and set the transmission jack.
NOTICE
Position the attachment so that the jack supports the engine oil pan and the sub-frame can be lowered.
I. Remove the four engine mount nuts for both engine mounts as shown in the illustration.
J. Mark the head of the attachment bolts on the backside of the front frame assembly.
K. Raise the transmission jack until both of the engine mounts lift off the front suspension cross member.
L. Remove the 4 bolts from the side rail plates.
M. Loosen the two nuts of the front suspension cross member.
N. Using the markings, loosen the two bolts five turns.
NOTICE
Do not remove the bolts or nuts.
O. Remove the four bolts and the two stabilizer bar brackets.
P. Remove the front stabilizer bar in the direction illustrated.
Q. Remove the power steering gear assembly in the direction shown in the illustration.
17. Degrease the tie rod ends, EPS spline, and cross member to EPS bolt contact surface.
NOTICE
Failure to degrease these components will prevent the proper amount of torque from being applied to their related attachment hardware.
18. Install the NEW power steering gear assembly by carefully inserting it into the position from the left side of the vehicle.
19. Install the AWD EPS components in the reverse order of removal. Please note that the torque specifications are included in Figures 25 and 26.
NOTICE
Only NEW clips (P/N 90468-16039) can be used for this repair. Do NOT re-use OLD clips.
20. Inspect and adjust wheel alignment.
21. Initialize rotation angle sensor and calibrate torque sensor zero point.
For complete initialization procedures, refer to E-TAS / TIS library, applicable model and model year Repair Manual:
- 2006 4WD GS300:
Power Assist Systems - Electronic Power Steering System - "Power Steering: Electronic Power Steering System: Calibration"
- 2007 / 2008 / 2009 / 2010 / 2011 4WD GS350:
Power Assist Systems - Electronic Power Steering System - "Power Steering: Electronic Power Steering System: Calibration"
- 2006 / 2007 / 2008 / 2009 / 2010 4WD IS250:
Power Assist Systems - Electronic Power Steering System - "Power Steering: Electronic Power Steering System: Calibration"
22. After the repair is complete, road test the vehicle to confirm the notchy steering feel condition is NO longer present.
NOTE:
Issue of this Technical Service Bulletin is to ensure that proper repair information is available.
IT DOES NOT CONSTITUTE AN AUTHORIZATION FOR REPAIR. Normal provisions of the formal warranty policy, as applicable, will apply.