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Front Suspension System Buick LaCrosse I

Suspension Front 8 illustrations ~3410 words

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
1 Front Lower Control Arm Ball Stud to Steering Knuckle Nut20 N.m + 120 degrees15 lb ft + 120 degrees
Front Lower Control Arm Mounting Nuts125 N.m92 lb ft
Front Lower Control Ball Stud Nuts to Control Arm68 N.m50 lb ft
Front Stabilizer Shaft Bracket Bolt42 N.m31 lb ft
Front Stabilizer Shaft Link Nut23 N.m17 lb ft
Front Suspension Strut Shaft Nut75 N.m55 lb ft
Front Suspension Strut Upper Mounting Nuts33 N.m24 lb ft
Front Suspension Strut to Steering Knuckle Nuts120 N.m89 lb ft
Wheel Bearing/Hub Bolts130 N.m96 lb ft
1 Tighten the nut in order to align the cotter pin hole with the front lower control arm ball stud. Do NOT loosen the nut in order to align the cotter pin hole.

Fastener Tightening Specifications

Removal Procedure

CAUTIONFailure to disconnect intermediate shaft from rack and pinion stub shaft can result in damage to steering gear and/or intermediate shaft. This damage can cause loss of steering control which could result in personal injury.
  1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  2. Remove the left tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  3. Remove the pinch bolt from the lower intermediate steering shaft. Refer to «Intermediate Steering Shaft Replacement»(/buick/lacrosse/i-2004-2009/remont/ignition-switchsteering-lock/#steering-wheel-steering-column) in Steering Wheel and Column.
  4. Loosen all the insulator clamp bolts from the frame.
  5. Place a jackstand under the center of the powertrain frame rear crossmember.
  6. Remove the 2 rear frame to body bolts.
  7. Lower the rear of the frame enough to gain access to the stabilizer shaft.
  8. Remove the insulator clamp bolts from the frame.
  9. Disconnect the stabilizer shaft links from the stabilizer shaft.
  10. Remove the stabilizer shaft from the left side of the vehicle.

Installation Procedure

  1. Loosely install the stabilizer shaft to the vehicle.
  2. Connect the stabilizer shaft links to the stabilizer shaft. Do not tighten at this time.
  3. Install the insulator clamps and bolts to the frame. Tighten: Tighten the stabilizer shaft clamp bolts to 42 N.m (31 lb ft).
  4. Raise the frame into position while guiding the steering shaft onto the steering gear.
  5. Install the rear powertrain frame bolts. Tighten: Tighten the bolts to 160 N.m (118 lb ft).
  6. Remove the jackstand.
  7. Install the pinch bolt to the steering shaft and tighten. Refer to «Intermediate Steering Shaft Replacement»(/buick/lacrosse/i-2004-2009/remont/ignition-switchsteering-lock/#steering-wheel-steering-column) in Steering Wheel and Column.
  8. Tighten the stabilizer link nuts. Tighten: Tighten the stabilizer shaft link nut to 60 N.m (44 lb ft).
  9. Install the left tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  10. Lower the vehicle.
  1. Raise the vehicle and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  2. Remove the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  3. Remove the stabilizer shaft link bolt and nut.
  4. Remove the stabilizer shaft link from the vehicle.
  1. Install the stabilizer link into the vehicle.
  2. Install the stabilizer shaft link bolt and nut. Tighten: Tighten the stabilizer shaft link nut to 23 N.m (17 lb ft).
  3. Install the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  4. Lower the vehicle.
  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  2. Remove the left and right side stabilizer shaft insulator clamp bolts.
  3. Remove the left and right side stabilizer shaft insulator clamp.
  4. Remove the left and right side stabilizer shaft insulators (1) from the stabilizer shaft (2).
  1. Install the left and right side stabilizer shaft insulators (1) to the stabilizer shaft (2).
  2. Install the left and right side stabilizer shaft insulator clamps.
  3. Install the left and right side stabilizer shaft insulator clamp bolts. Tighten: Tighten the bolts to 42 N.m (31 lb ft).
  4. Lower the vehicle.

Tools Required

J 41820 Ball Joint/Stud Separator. See Special Tools .

  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  2. Remove the tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  3. Drill a pilot hole through the rivets.
  4. Drill the remainder of the rivets.
  5. Use a hammer and a chisel in order to remove the remainder of the rivet heads.
  6. Remove the cotter pin from the ball stud.
  7. Loosen the ball stud nut.
  8. Install the J 41820 over the ball stud and lower control arm. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  9. Rotate the ball stud nut counterclockwise in order to separate the ball stud from the steering knuckle.
  10. Remove the J 41820 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  11. Remove the ball stud nut.
  12. Remove the ball stud from the lower control arm.
  1. Install the ball stud to the lower control arm.
  2. Install the NEW ball stud bolts facing down, away from the ball stud.
  3. Install the NEW ball stud nuts. Tighten: Tighten the NEW ball stud nuts to 68 N.m (50 lb ft).
  4. Install the ball stud to the steering knuckle.
  5. Install the ball stud castle nut. Tighten: Tighten the nut to 20 N.m (15 lb ft) plus an additional 120 degrees
  6. Install a new cotter pin and bend the ends.
  7. Install the tire and wheels. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  8. Lower the vehicle.
  9. Check the wheel alignment. Refer to «Measuring Wheel Alignment»(/buick/lacrosse/i-2004-2009/remont/wheel-alignment/#wheel-alignment-system__measuring-wheel-alignment) in Wheel Alignment.

J 42129 Wheel Hub Remover

  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  2. Remove the tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  3. Disconnect the wheel speed sensor electrical connector (2), if equipped.
  4. Remove the wheel speed sensor electrical connector from the bracket, if equipped.
  5. Remove the front wheel drive shaft nut (2). Insert a drift or flat-bladed tool (1) into the caliper and rotor to prevent from turning.
  6. Remove the brake rotor. Refer to «Brake Rotor Replacement - Front (J65, JL9)»(/buick/lacrosse/i-2004-2009/remont/mechanical-hydraulic/#disc-brake-system__brake-rotor-replacement-front-j65) in Disc Brakes.
  7. Use 3 wheel nuts in order to attach the J 42129 to the wheel bearing/hub.
  8. Use the J 42129 in order to push the wheel drive shaft out of the wheel bearing/hub.
  9. Remove and DISCARD the wheel bearing/hub bolts. Remove the J 42129 from the hub.
  10. Remove the wheel bearing/hub and splash shield-noting the position of the shield for re-installation.
  1. Install the wheel bearing/hub with the splash shield as noted during removal.
  2. Install NEW wheel bearing/hub bolts. Tighten: Tighten the NEW wheel bearing/hub bolts to 130 N.m (96 lb ft).
  3. Install the brake rotor and caliper. Refer to «Brake Rotor Replacement - Front (J65, JL9)»(/buick/lacrosse/i-2004-2009/remont/mechanical-hydraulic/#disc-brake-system__brake-rotor-replacement-front-j65) in Disc Brakes.
  4. Install the front wheel drive shaft nut. Insert a drift on a flat-bladed tool into caliper and rotor to prevent the rotor from turning. Tighten: Tighten the front wheel drive shaft nut to 160 N.m (118 lb ft).
  5. Install the wheel speed sensor electrical connector to the bracket, if equipped.
  6. Connect the wheel speed sensor electrical connector (2), if equipped.
  7. Install the tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  8. Lower the vehicle.
  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  2. Remove the bearing/hub assembly. Refer to «Wheel Bearing/Hub Replacement - Front»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system) .
  3. Disconnect the front lower control arm ball stud. Refer to «Lower Control Arm Replacement»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system) .
  4. Disconnect the outer tie rod end from the steering knuckle. Refer to «Rack and Pinion Outer Tie Rod End Replacement»(/buick/lacrosse/i-2004-2009/remont/manual-power-steering/#power-steering-system) in Power Steering System.
  5. Scribe the strut to the knuckle.
  6. Remove the bolts and nuts attaching the strut to the knuckle.
  7. Remove the knuckle from the vehicle.
  1. Install the knuckle to the vehicle.
  2. Install the through bolts and nuts attaching the strut to the knuckle. Tighten: Tighten the through bolts and nuts to 120 N.m (89 lb ft).
  3. Connect the outer tie rod to the steering knuckle. Refer to «Rack and Pinion Outer Tie Rod End Replacement»(/buick/lacrosse/i-2004-2009/remont/manual-power-steering/#power-steering-system) in Power Steering System.
  4. Connect the front lower control arm ball stud to the knuckle. Refer to «Lower Control Arm Replacement»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system) .
  5. Install the front wheel drive shaft bearing. Refer to «Wheel Bearing/Hub Replacement - Front»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system) .
  6. Lower the vehicle.
  7. Inspect the front wheel alignment and adjust if necessary. Refer to «Measuring Wheel Alignment»(/buick/lacrosse/i-2004-2009/remont/wheel-alignment/#wheel-alignment-system__measuring-wheel-alignment) in Wheel Alignment.

J 41820 Ball Joint/Stud Separator. See Special Tools .

Note. Use only the recommended tools for separating the ball joint from the knuckle. Do NOT hammer or pry the ball joint from the knuckle. Failure to use the recommended tools may cause damage to the ball joint and seal.

  1. Turn the steering wheel in order to move the front of the applicable wheel to the outboard most position.
  2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  3. Remove the tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  4. If applicable, disconnect the ABS wheel speed sensor connector (2).
  5. If applicable, disconnect the ABS wheel speed sensor jumper harness from the harness retainer clips.
  6. Remove the cotter pin (1) from the ball stud (3).
  7. Loosen the ball stud nut (2).
  8. Install the J 41820 over the ball stud and lower control arm as shown. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  9. Rotate the ball stud nut counterclockwise in order to separate the ball stud from the steering knuckle.
  10. Remove the J 41820 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  11. Remove the ball stud nut.
  12. Remove the lower control arm bolts and nuts.
  13. Remove the lower control arm.
  1. Install the lower control arm.
  2. Install the control arm bolts and nuts. Do not tighten at this time.
  3. Install the ball stud to the knuckle.
  4. Install the ball stud castle nut. Tighten: Tighten the nut to 20 N.m +120 degrees (15 lb ft +120 degrees).
  5. If necessary, tighten the ball stud castle nut in order to align the ball stud castle nut slot (1) to the ball stud cotter pin hole (2) as shown.
  6. Install a NEW cotter pin and bend the ends as shown in either example.
  7. If applicable, connect the ABS wheel speed sensor jumper harness to the harness retainer clips.
  8. If applicable, connect the ABS wheel speed sensor connector.
  9. Install the lower control arm nuts. Tighten: Tighten the lower control arm nuts to 125 N.m (92 lb ft).
  10. Install the tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  11. Lower the vehicle.
  1. J 21474-01 Control Arm Bushing Set. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . J 21474-27 1/2 Inch Puller Bolt Thrust Bearing J 21474-2 Bushing Installer Remover. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . J 21474-4 Nut J 21474-13 Control Arm Bushing Installer. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  2. J 23444-A High Pressure Lubricant. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  3. J 34126 Driven Sprocket Support Bearing Installer. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  4. J 35379 Front Knuckle Support. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  1. Remove the lower control arm. Refer to «Lower Control Arm Replacement»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system) .
  2. Secure the lower control arm in a vice.
  3. Mark the lower control arm along the flat edge of the bushing flange.
  4. Assemble the following bushing removal tools as shown: J 21474-27 J 21474-13 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . J 34126 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . J 35379 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . J 21474-2 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . J 21474-4
  5. Tighten J 21474-4 .
  6. Disassemble the bushing removal tools.
  1. Align the flat edge of the bushing flange to the mark in the control arm (1). Ensure that the flat edge of the bushing flange is 30 degrees (2) from the centerline of the lower control arm. Ensure that the thin slot in the bushing is facing outboard.
  2. Insert the bushing into the control arm.
  3. Assemble the following bushing installation tools as shown: J 21474-27 J 21474-13 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . J 21474-5 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . J 21474-4
  4. Tighten J 21474-4 .
  5. Disassemble the bushing installation tools.
  6. Install the lower control arm. Refer to «Lower Control Arm Replacement»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system) .
  1. J 21474-01 Control Arm Bushing Service Set. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  2. J 21474-5 Control Arm Bushing Receiver. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  1. Remove the lower control arm. Refer to «Lower Control Arm Replacement»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system) .
  2. Secure the lower control arm in a vise.
  3. Assemble the bushing removal tools as indicated: The nut (1) The J 21474-01 washer (2). See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . The J 21474-01 bearing (3). See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . The J 21474-5 (4). See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . The J 21474-01 puller bolt (5). See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  4. Tighten the puller bolt (5) until the bushing is removed.
  5. Disassemble the J 21474-01 and J 21474-5 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  1. Lubricate the bushing with liquid hand soap or equivalent.
  2. Assemble the following bushing installation tools as indicated : The nut (1) The J 21474-01 washer (2). See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . The J 21474-01 bearing (3). See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . The J 21474-5 (4). See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . The J 21474-01 puller bolt (5). See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  3. Tighten the puller bolt (5) until the bushing is installed into the control arm.
  4. Disassemble the J 21474-01 and J 21474-5 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  5. Remove the control arm from the vice.
  6. Install the lower control arm. Refer to «Lower Control Arm Replacement»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system) .

J 6627-A Tie Rod Puller. See Special Tools .

  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  2. Remove the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  3. Remove the brake caliper and bracket. Hang the caliper and the bracket from the vehicle. DO NOT allow the caliper and the bracket to hang by the brake hose. Refer to «Brake Caliper Replacement - Front (J65, JL9)»(/buick/lacrosse/i-2004-2009/remont/mechanical-hydraulic/#disc-brake-system) in Disc Brakes.
  4. Remove the brake rotor. Refer to «Brake Rotor Replacement - Front (J65, JL9)»(/buick/lacrosse/i-2004-2009/remont/mechanical-hydraulic/#disc-brake-system__brake-rotor-replacement-front-j65) in Disc Brakes.
  5. Use the J 6627-A in order to extract the stud (1) from the hub (2). See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  1. Install a replacement stud in the wheel hub.
  2. Add enough washers (3) in order to draw the stud into the hub (2).
  3. Install the wheel nut (1) with the flat side against the washers (3).
  4. Tighten the wheel nut (1) until the wheel stud is fully seated against the hub flange.
  5. Back off the wheel nut (1) and remove the washers (3).
  6. Install the brake rotor. Refer to «Brake Rotor Replacement - Front (J65, JL9)»(/buick/lacrosse/i-2004-2009/remont/mechanical-hydraulic/#disc-brake-system__brake-rotor-replacement-front-j65) in Disc Brakes.
  7. Install the brake caliper and bracket. Refer to «Brake Caliper Replacement - Front (J65, JL9)»(/buick/lacrosse/i-2004-2009/remont/mechanical-hydraulic/#disc-brake-system) in Disc Brakes.
  8. Install the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  9. Lower the vehicle.
  1. Remove the strut upper mounting nuts.
  2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  3. Remove the tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  4. Scribe the strut to the knuckle.
  5. Remove the strut lower bolts and nuts.
  6. Remove the strut.
  1. Install the strut.
  2. Install the strut upper mounting nuts. Tighten: Tighten the nuts to 33 N.m (24 lb ft).
  3. Install the strut lower bolts and nuts.
  4. Align the strut to the mark on the knuckle. Tighten: Tighten the strut lower nuts to 120 N.m (89 lb ft).
  5. Install the tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/i-2004-2009/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
  6. Lower the vehicle.
  7. Align the front wheels. Refer to «Measuring Wheel Alignment»(/buick/lacrosse/i-2004-2009/remont/wheel-alignment/#wheel-alignment-system__measuring-wheel-alignment) in Wheel Alignment.

Suspension Strut Disposal

CAUTIONUse the proper eye protection when drilling to prevent metal chips from causing physical injury.
  1. Clamp the strut in a vise horizontally with the rod (1) completely extended.
  2. Drill a hole in the strut at the center of the end cap (3) using a 5 mm (3/16 in) drill bit. Gas or a gas/oil mixture will exhaust when the drill bit penetrates the strut. Use shop towels in order to contain the escaping oil.
  3. Remove the strut from the vise.
  4. Hold the strut over a drain pan vertically with the hole down.
  5. Move the rod (1) in and out of the tube (2) to completely drain the oil from the strut.
  1. J 42991 Strut Rod Nut Socket. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  2. J 45400 Strut Spring Compressor. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .

Disassembly Procedure

  1. Remove the strut from the vehicle. Refer to «Strut Assembly Replacement»(/buick/lacrosse/i-2004-2009/remont/suspension-rear/#rear-suspension-system) .
  2. Install the strut (2) in the J 45400 (1). See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  3. Turn the spring compressor forcing screw (1) until the coil spring (2) is compressed.
  4. Use a 45 TORX® socket in order to hold the strut shaft. Remove the upper strut mount nut by turning with J 42991 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  5. Remove the strut from the J 45400 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  6. Loosen the compressor forcing screw (1) until the upper strut mount and coil spring (2) may be removed.
  7. Remove the upper strut mount and the coil spring from the J 45400 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .

Assembly Procedure

  1. Install the coil spring and upper strut mount to the J 45400 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  2. Turn the spring compressor forcing screw (1) until the coil spring is compressed.
  3. Install the strut to the coil spring and upper strut mount.
  4. Install the strut retaining nut. Using the J 42991 and a 45 TORX® socket, install the strut mount nut. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) . Tighten: Tighten the strut mount nut to 75 N.m (55 lb ft).
  5. Remove the strut from the J 45400 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/suspension-front/#front-suspension-system__special-tools) .
  6. Install the strut to the vehicle. Refer to «Strut Assembly Replacement»(/buick/lacrosse/i-2004-2009/remont/suspension-rear/#rear-suspension-system) .

General Description

The front suspension has 2 primary purposes

  1. Isolate the driver from irregularities in the road surface.
  2. Define the ride and handling characteristics of the vehicle.

The front suspension absorbs the impact of the tires travelling over irregular road surfaces and dissipates this energy throughout the suspension system. This process isolates the vehicle occupants from the road surface. The rate at which the suspension dissipates the energy and the amount of energy that is absorbed is how the suspension defines the vehicles ride characteristics. Ride characteristics are designed into the suspension system and are not adjustable. The ride characteristics are mentioned in this description in order to aid in the understanding of the functions of the suspension system. The suspension system must allow for the vertical movement of the tire and wheel assembly as the vehicle travels over irregular road surfaces while maintaining the tire's horizontal relationship to the road.

This requires that the steering knuckle be suspended between a lower control arm and a strut assembly. The lower control arm attaches from the steering knuckle at the outermost point of the control arm. The attachment is through a ball and socket type joint. The innermost end of the control arm attached at 2 points to the vehicle frame through semi-rigid bushings. The upper portion of the steering knuckle is attached to a strut assembly. The strut assembly then connects to the vehicle body by way of an upper bearing. The steering knuckle is allowed to travel up and down independent of the vehicle body structure and frame.

This up and down motion of the steering knuckle as the vehicle travels over bumps is absorbed predominantly by the coil spring. This spring is retained under tension over the strut assembly. A strut is used in conjunction with this system in order to dampen out the oscillations of the coil spring. A strut is a basic hydraulic cylinder. The strut is filled with oil and has a moveable shaft that connects to a piston inside the strut. Valves inside the shock absorber offer resistance to oil flow and consequently inhibit rapid movement of the piston and shaft. Each end of the shock absorber is connected in such a fashion to utilize this recoil action of a spring alone. Each end of the strut is designed as the connection point of the suspension system to the vehicle and acts as the coil spring seat. This allows the strut to utilize the dampening action to reduce the recoil of a spring alone. The lower control arm is allowed to pivot at the vehicle frame in a vertical fashion. The ball joint allows the steering knuckle to maintain the perpendicular relationship to the road surface.

Front suspensions systems utilize a stabilizer shaft. The stabilizer bar connects between the left and right strut assemblies through the stabilizer link and stabilizer shaft insulators. This bar controls the amount of independent movement of the suspension when the vehicle turns. Limiting the independent movement defines the vehicles handling characteristics on turns.

Special Tools

Special Tools Illustration Tool Number/Description J 6627-A Tie Rod Puller J 21474-01 Control Arm Bushing Set J 21474-2 Bushing Installer Remover J 21474-4 1/2 Inch Nut J 21474-5 Bushing Receiver J 21474-13 Control Arm Bushing Installer J 21474-27 1/2 Inch Puller Bolt Thrust Bearing J 23444-A Extreme Press Lubricant - 1/4 Ounce Tube J 34126 Sprocket Support Bearing Installer J 35379 Front Knuckle Support J 41820 Ball Joint Separator J 42129 Wheel Hub Remover J 42991 Strut Rod Nut Socket J 45400 Strut Spring Compressor

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