Drivetrain - Vibration/Drone Between 55-60 MPH
L-SB-0147-08October 21, 2008
Abnormal Driveline Drone/Vibration Between 55-65 MPH
Service Category
Drivetrain
Section
Drive Shaft/Propeller Shaft
Market
USA
Applicability
Introduction
Some customers may complain about a drone noise or slight vibration between 55 - 65 mph with slight engine load on LS 460 vehicles. Use the following repair procedure to address customer concerns.
This condition should NOT be mistaken with tire vibration due to excessive Road Force Variation (RFV) or torque converter flex lock-up.
Warranty Information
APPLICABLE WARRANTY
^ This repair is covered under the Lexus Comprehensive Warranty. This warranty is in effect for 48 months or 50,000 miles, whichever occurs first, from the vehicles in-service date.
^ Warranty application is limited to correction of a problem based upon a customers specific complaint.
Parts Information
Required Tools & Equipment
Diagnostic Procedure
1. Ensure that the condition is NOT engine speed or gear dependent. Does the condition occur in multiple gears (e.g. 6 7 8)?
^ YES - Continue to step 2.
^ NO - This TSIB does NOT apply. Refer to the Technical Information System (TIS) for the applicable symptoms.
2. Are all the tires RFV under 10 lbs?
^ YES - Continue to the Repair Procedure.
^ NO - Correct the RFV condition and re-test.
3. If the first two steps are satisfied for the condition it may be related to the procedure below. This condition is related to vehicle speed - NOT gear selection or engine speed.
1. Perform driveshaft indexing.
A. Place matchmarks on the differential flange dynamic damper and propeller shaft flange as shown in Figure 1.
B. Remove the 3 nuts and bolts from the dynamic damper to the rear differential flange.
C. Rotate the driveshaft 120 degrees clockwise then reinstall and torque the nuts and bolts. Torque: 79 N*m (805 kg*cm, 58 ft*lbf)
D. Adjust driveshaft length and angle per the Repair Manual to reduce deflection of the dynamic damper.
Refer to the Technical Information System (TIS):
^ 2007 / 2008 LS 460 Drivetrain - Driveshaft/Propeller Shaft - "Propeller Shaft: Propeller Shaft Assembly Installation"
E. Test drive vehicle and repeat procedure until the best of the 3 driveshaft positions is determined.
2. Replace the front upper rear suspension member stoppers (shown in Figure 2) for the rear suspension member sub-assembly.
A. Support the differential with a transmission jack.
B. Remove the two front mounting bolts and lower the sub-frame enough to replace the rubber stoppers.
C. Install in reverse order.
Torque: 127 N*m (1295 kg~cm, 94 ft*lbf)
3. Install the reinforcement.
A. Slide the front seats all the way forward.
B. Remove the rear seats.
Refer to TIS:
^ 2007 LS 460 Vehicle Interior - Seat - "Seat Rear Seat Assembly (for Power Seat) / (for Fixed Seat Type): Removal"
^ 2008 LS 460 Vehicle Interior - Seat - "Seat Rear Seat Assembly (for Power Seat) / (for Fixed Seat Type): Removal"
C. Lower headliner and slide forward to windshield allowing it to rest on the dashboard and front seats. This will allow access to the needed area without having to remove the headliner from the vehicle.
Refer to TIS:
^ 2007 LS 460 Vehicle Interior - Interior Panels/Trim - "Interior: Roof Headlining (for Standard Body) / (for Long Body): Removal"
^ 2008 LS 460 Vehicle Interior - Interior Panels/Trim - "Interior: Roof Headlining (for Standard Body) / (for Long Body): Removal"
D. For the rear support assembly shown in Figure 3 remove the two nuts (1, 2) that mount the radio antenna the wire harness mount (3) and clip (4). Allow radio antenna to hang down. Remove nuts (5, 6).
E. Wrap felt from the noise kit around the tab of the radio antenna.
F. Before installing hold the reinforcement against the rear roof panel header to reference the correct location holes.
G. Clean any dust or oil out of the hatched area shown in Figure 5 (Frame Back Window UPR Outer). Apply tube (150 mL) of panel bonding adhesive 3M(TM) Automix Bond 8115 (or equivalent) into the hatched area.
NOTE
Steps H - K should be completed within 45 minutes due to adhesive hardening.
H. Install the reinforcement and tighten the original nuts (1, 2 in Figure 6).
Torque: 8 N*m (81.5 kg*cm, 71 in*lbf)
I. Tighten nuts (3, 4 in Figure 6) (P/N 90080-17244).
Torque: 8 N*m (81.5 kg*cm, 71 in*lbf)
J. Tighten bolt (5 in Figure 6) (P/N 90080-11226).
Torque: 5.5 N*m (56 kg*cm, 49 in*lbf)
NOTE
Steps K - M can be completed after steps N - Q to allow for curing.
K. Remove nut (4) in Figure 6. This nut is only used to secure the panel during adhesive hardening and can be removed after an hour of curing.
L. Install the radio antenna in the original position. Tighten nuts (8 9 in Figure 6).
Torque: 14 N*m (143 kg*cm, 124 in*lbf)
M. Install the wire harness mount on the nut (4).
N. Install the damper sheets.
Remove the sunroof support cross brace brackets shown in Figure 7 to gain access to the roof panel.
O. Peel back the paper on the damper sheets and locate as shown in Figures 8 and 9. Do NOT overlap the damper sheets in the center of the vehicle.
P. Replace the rear sunroof support brackets.
Q. Replace the headliner and rear seats.
NOTE
Replace the clip (P/N 62217-12050) on the C-pillar panel, as shown in Figure 10, if it becomes damaged during removal.
R. Allow vehicle to sit undisturbed for 24 hours after installation to allow panel bonding adhesive to cure.
4. Test drive the vehicle to verify the condition has been repaired.