Suspension: Diagnosis Lexus LS IV

PROBLEM SYMPTOMS TABLE

HINT

Use the table below to help determine the cause of the problem symptom. The potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.

Suspension system

PROBLEM SYMPTOMS

HINT

Use the table below to help determine the cause of the problem symptom. The potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.

Suspension system

PROBLEM SYMPTOMS

Scheme 26

Scheme 27

Scheme 28

Scheme 29

Scheme 30

Scheme 31

Scheme 32

Scheme 33

Scheme 34

Scheme 35

Scheme 36

Scheme 37

Scheme 38

Scheme 39

Scheme 40

1. INSPECT TIRES (See «INSPECTION»(ref-349710-S18741064512009120800000) )
2. MEASURE VEHICLE HEIGHT (w/o Air Suspension) Bounce the vehicle at the corners up and down to stabilize the suspension and inspect the vehicle height. Standard vehicle height STANDARD VEHICLE HEIGHT - Front (A - B) Rear (D - C) Standard Body 18 in. Wheel 91 mm (3.583 in.) 76 mm (2.992 in.) Standard Body 19 in. Wheel 91 mm (3.583 in.) 76 mm (2.992 in.) Long Body 18 in. Wheel 91 mm (3.583 in.) 76 mm (2.992 in.) Long Body 19 in. Wheel 91 mm (3.583 in.) 76 mm (2.992 in.) Measuring points: A: Ground clearance of front wheel center B: Ground clearance of front center position of front No. 2 suspension lower arm assembly front bush installation C: Ground clearance of pit center of the attachment rear suspension arm D: Ground clearance of rear wheel center NOTE: Before inspecting the wheel alignment, adjust the vehicle height to the specified value. If the vehicle height is not as specified, adjust the height by pressing down on the vehicle several times to stabilize the suspension.
3. MEASURE VEHICLE HEIGHT (w/ Air Suspension) Bounce the vehicle at the corners up and down to stabilize the suspension and inspect the vehicle height. Standard vehicle height STANDARD VEHICLE HEIGHT - Front (A - B) Rear(D-C) 18 in. Wheel 98 mm (3.858 in.) 93 mm (3.661 in.) 19 in. Wheel 98 mm (3.858 in.) 93 mm (3.661 in.) Measuring points: A: Ground clearance of front wheel center B: Ground clearance of front center position of front No. 2 suspension lower arm assembly front bush installation C: Ground clearance of pit center of the attachment rear suspension arm D: Ground clearance of rear wheel center NOTE: Before inspecting the wheel alignment, adjust the vehicle height to the specified value. If the vehicle height is not as specified, adjust the height by pressing down on the vehicle several times to stabilize the suspension.
4. INSPECT TOE-IN Bounce the vehicle up and down at the corners to stabilize the suspension and inspect toe-in. Toe-in (w/ Air Suspension) TOE-IN REFERENCE Toe-in (total) B - A: 0 +/-2 mm (0 +/-0.08 in.) Toe-in (w/o Air Suspension) TOE-IN REFERENCE Toe-in (total) B - A: 1 +/-2 mm (0.04 +/-0.08 in.) If toe-in is not within the specified range, adjust it at the rack ends.
5. ADJUST TOE-IN Measure the thread lengths of the right and left rack ends. Standard: Difference in thread length of 1.5 mm (0.059 in.) or less Remove the rack boot set clips. Loosen the tie rod end lock nuts. Adjust the rack ends if the difference in thread length between the right and left rack ends is not within the specified range. Extend the shorter rack end if the measured toe-in deviates toward the outer-side. Shorten the longer rack end if the measured toe-in deviates toward the inner-side. Turn the right and left rack ends by an equal amount to adjust toe-in. HINT: Try to adjust toe-in to the center of the specified range. Make sure that the lengths of the right and left rack ends are the same. Tighten the tie rod end lock nuts. Torque: 55.9 N*m (571 kgf*cm, 41 ft.*lbf) NOTE: Temporarily tighten the lock nut while holding the hexagonal part of the steering rack end so that the lock nut and the steering rack end do not turn together. Hold the width across flat of the tie rod end and tighten the lock nut. Perform the VGRS system calibration (see «INITIALIZATION»(ref-349720-S01567451522009120800000) ). Place the boots on the seats and install the clips. HINT: Make sure that the boots are not twisted. Make sure that the clips' finger grips are positioned as shown in the illustration.
6. INSPECT WHEEL ANGLE Turn the steering wheel fully to the left and right and measure the turning angle. Standard wheel turning angle WHEEL TURNING ANGLE - Inside wheel Outside wheel: Reference Coll suspension 18 in. 41°45' (41.75°) 35°17' (35.28°) Coll suspension 19 in. 40°46' (40.77°) 34°40' (34.67°) Air suspension 18 in. 41°37' (41.62°) 35°11'(35.18°) Air suspension 19 in. 40°38' (40.63°) 34°34' (34.57°) If the right and left inside wheel angles differ from the specified range, check the right and left rack end lengths.
7. INSPECT CAMBER, CASTER AND STEERING AXIS INCLINATION Put the front wheels on the center of the alignment tester. Remove the center ornament. Install the camber-caster-steering axis inclination gauge at the center of the axle hub or drive shaft. Inspect the camber, caster and steering axis inclination. Standard camber inclination (unloaded) STANDARD CAMBER Item Camber Inclination Coll suspension (Standard body) Camber Left - right error -0°17' +/-45' (-0.28° +/-0.750) 30' (0.50°) or less Coll suspension (Long body) Camber Left - right error -0°17' +/-451 (-0.28° +/-0.750) 30' (0.50°) or less Air suspension Camber Left - right error -0°26' +/-451 (-0.43° +/-0.750) 30' (0.50°) or less Standard caster inclination (unloaded) STANDARD CAMBER Item Caster Inclination Coil suspension (Standard body) Caster Left - right error 6°37' +/-45' (6.62° +/-0.750) 45' (0.75°) or less Coil suspension (Long body) Caster Left - right error 6°37' +/-451 (6.62° +/-0.75°) 45' (0.75°) or less Air suspension Caster Left - right error 7°1'+/-45'(7.02°+/-0.75°) 45' (0.75°) or less Standard steering axis inclination (unloaded) STANDARD STEERING AXIS Item Steering axis Inclination Coil suspension (Standard body) Steering axis Left - right error 9°7' +/-45' (9.12° +/-0.75°) 30' (0.50°) or less Coil suspension (Long body) Steering axis Left - right error 9°7' +/-45' (9.12° +/-0.75°) 30' (0.50°) or less Air suspension Steering axis Left - right error 9°18'+/-45'(9.3°+/-0.75°) 30' (0.50°) or less NOTE: Inspect while the vehicle is empty. The maximum tolerance of right and left difference for the camber is 30' or less. The maximum tolerance of right and left difference for the caster is 45' or less. Remove the camber-caster-steering axis inclination gauge and attachment. Install the center ornament. If the caster and steering axis inclination are not within the specified values, after the camber has been correctly adjusted, recheck the suspension parts for damaged and/or worn out parts.
8. ADJUST CAMBER AND CASTER Lift up the vehicle so that there is no load on the tires. Place a mark (with spray, etc.) over the front right vehicle side attachment area of the crossmember, which is indicated in the illustration. Place a mark (with spray, etc.) over the front left vehicle side attachment area of the crossmember. Loosen areas as necessary so that the front suspension crossmember can move. Move the front suspension crossmember and adjust the camber and caster. Relative alignment change based on amount of suspension crossmember movement in each direction ALIGNMENT CHANGE AMOUNT REFERENCE - Alignment Change Amount Relative Amount of Movement Between Suspension Crossmember and Vehicle Body 1 Suspension Crossmember Turn Caster Camber Suspension Crossmember Installation Front Side LH Suspension Crossmember Installation Front Side RH LH RH LH RH Front to Rear Left to Right Front to Rear Left to Right -10' + 3' + 3' - 3' +1 mm (+ 0.0394 in.) - - - 1' Caster Camber Suspension Crossmember Installation Front Side LH Suspension Crossmember Installation Front Side RH LH RH LH RH Front to Rear Left to Right Front to Rear Left to Right + 3' - 10' - 3' + 3' - - +1 mm (+ 0.0394 in.) - 2 Suspension Crossmember Front to Rear Movement Caster Camber Suspension Crossmember Installation Front Side LH Suspension Crossmember Installation Front Side RH LH RH LH RH Front to Rear Left to Right Front to Rear Left to Right -7.5' -7.5' +/- 0' +/- 0' +1 mm (+ 0.0394 in.) - +1 mm (+ 0.0394 in.) - 2' Caster Camber Suspension Crossmember Installation Front Side LH Suspension Crossmember Installation Front Side RH LH RH LH RH Front to Rear Left to Right Front to Rear Left to Right + 7.5' + 7.5' +/- 0' +/- 0' -1 mm (- 0.0394 in.) - -1 mm (- 0.0394 in.) - 3 Suspension Crossmember Left to Right Movement Caster Camber Suspension Crossmember Installation Front Side LH Suspension Crossmember Installation Front Side RH LH RH LH RH Front to Rear Left to Right Front to Rear Left to Right + 1' - 1' + 7' - 7' - +1 mm (+ 0.0394 in.) - +1 mm (0.0394 in.) (+ 0.0394 in.) 3' Caster Camber Suspension Crossmember Installation Front Side LH Suspension Crossmember Installation Front Side RH LH RH LH RH Front to Rear Left to Right Front to Rear Left to Right - 1' + 1' - 7' + 7' - -1 mm (- 0.0394 in.) - -1 mm (- 0.0394 in.) Tighten the areas loosened previously.
9. ADJUST CAMBER If the front suspension crossmember's left to right camber value is not as specified even though the camber and caster adjustment was performed, replace the No. 1 arm attachment plate inner and No. 2 arm attachment plate inner. Then perform the camber adjustment again. Standard STANDARD - No. 1 Arm Attachment Plate Inner No. 2 Arm Attachment Plate Inner Camber Angle Change Caster Angle Change - RH LH RH LH - - Arm Attachment Part No. and Distinguishing Color Standard Part 48614-50010 (Yellow) 48617-50010 (Yellow) 48614-50020 (White) 48617-50020 (White) 0 (Standard) 0 (Standard) + 2 mm Part 48614-50030 (Pink) 48617-50030 (Pink) 48614-50050 (Blue) 48617-50050 (Blue) + 16.41 + 2.51 HINT: For +2 mm parts, the upper arm installation hole is further toward the outside of the vehicle compared to standard parts.
10. INSPECT FRONT SUSPENSION Inspect the front suspension member. Measure the dimension between the center of the installation bolts of the front No. 2 suspension lower arm. Standard length: 788 mm (31.0236 in.) If the result is not within the specification, replace the front suspension member. Inspect the front No. 1 suspension lower arm. Remove the front No. 1 suspension lower arm (see «REMOVAL»(ref-349722-S31569215582009120800000) ). Measure the dimension between the center of the front No. 1 suspension lower arm bush and the ball joint stud. Standard length: 385.5 mm (15.177 in.) HINT: If the dimension of the front suspension lower arm changes 2 mm (0.0787 in.), the camber will change approximately 15' (0.25°). Inspect the front No. 2 suspension lower arm. Remove the front No. 2 suspension lower arm (see «REMOVAL»(ref-349722-S31569215582009120800000) ). Measure the dimension between the center of the front suspension lower arm bush and position A. Standard length: 315.6 mm (12.425 in.) HINT: If the dimension of the front suspension lower arm changes 2 mm (0.0787 in.), the camber will change approximately 15' (0.25°). Inspect the front No. 1 suspension upper arm. Remove the front No. 1 suspension upper arm (see «REMOVAL»(ref-349722-S30196817942009120800000) ). Measure the dimension between the center of the front No. 1 suspension upper arm bush and the ball joint stud. Standard length: 235.8 mm (9.283 in.) HINT: If the dimension of the front suspension upper arm changes 2 mm (0.0787 in.), the camber will change approximately 15' (0.25°). Inspect the front No. 2 suspension upper arm. Remove the front No. 2 suspension upper arm (see «REMOVAL»(ref-349722-S30196817942009120800000) ). Measure the dimension between the center of the front No. 2 suspension upper arm bush and the ball joint stud. Standard length: 224.5 mm (8.839 in.) HINT: If the dimension of the front suspension upper arm changes 2 mm (0.0787 in.), the camber will change approximately 15' (0.25°).

ON-VEHICLE INSPECTION

1. INSPECT FRONT SUSPENSION UPPER ARM BALL JOINT RATTLE Jack up the vehicle. Move the front suspension upper arm up and down by hand, and check for rattle. OK: No rattle.

INSPECTION

1. INSPECT FRONT NO. 1 SUSPENSION UPPER ARM ASSEMBLY LH Inspect the turning of the upper ball joint. Install the installation nut to the ball joint stud. Move the stud back and forth 5 times. Using a torque wrench, turn the nut continuously at a rate of 2 to 5 seconds per turn and take the torque reading on the fifth turn. Standard turning torque: 3.5 N*m (35.7 kgf*cm, 30.9 in.*lbf) or less If the value is not within the specified range, replace the front suspension upper arm with a new one. Check the dust boots for cracks or grease leakage.
2. INSPECT FRONT NO. 2 SUSPENSION UPPER ARM ASSEMBLY LH Inspect the turning of the upper ball joint. Install the installation nut to the ball joint stud. Move the stud back and forth 5 times. Using a torque wrench, turn the nut continuously at a rate of 2 to 5 seconds per turn and take the torque reading on the fifth turn. Standard turning torque: 3.5 N*m (35.7 kgf*cm, 30.9 in.*lbf) or less If the value is not within the specified range, replace the front suspension upper arm with a new one. Check the dust boots for cracks or grease leakage.

1. INSPECT FRONT LOWER SUSPENSION ARM BALL JOINT RATTLE Jack up the vehicle. Move the front No. 2 suspension lower arm up and down by hand, and check for rattle. OK: No rattle.

1. INSPECT FRONT NO. 2 SUSPENSION LOWER ARM Temporarily install the nut, and flip the ball joint stud back and forth 5 times as shown in the illustration. Use a torque wrench to turn the nut continuously at a rate of 3 to 5 seconds per turn. Take the torque reading on the fifth turn. Standard turning torque: 3.0 N*m (30.6 kgf*cm, 26.6 in.*lbf) If the result is not as specified, replace the front No. 2 suspension lower arm. Check the dust boot for cracks or grease leakage.

1. INSPECT REAR SHOCK ABSORBER ASSEMBLY LH Extend and compress the rear shock absorber. When extending and compressing the rear shock absorber at a constant speed, it can be moved without any abnormal resistance or noise and load is constant through the entire stroke. It also extends at a constant speed after being compressed. If there is any abnormality, replace the rear shock absorber with a new one. NOTE: When disposing of the rear shock absorber, see «DISPOSAL»(ref-349722-S01297877862009120800000) .