1990-2000 Lexus LS 400 Rear Conversion Kit Installation Manual

Take a look at our easy-to-follow 1990-2000 Lexus LS 400 Rear Conversion Kit Installation Manual to learn how to install your new Strutmasters air suspension conversion kit. Our step-by-step instructions include pictures to help you along the way.

Lexus LS 400 parts included in this kit:

  • 2 Coilover Strut Assemblies.

Getting Started

  1. Disconnect Battery
  2. Read general service precautions
  3. Wear Eye Protection
  4. Support the vehicle
  5. Remove air suspension parts
  6. Install conversion kit

Tools needed for installation:

  • Metric sockets
  • Metric wrenches
  • Torques bits
  • Floor jack or vehicle lift
  • Level work surface
  • Jack stands
  • General Tools

Rear Air Strut Removal GuideStep 1

Caution: A sudden release of pressure may cause personal injury or damage to the vehicle. The air suspension system is under pressure until the air supply lines are disconnected. Use the following precautions when servicing the air suspension system: Wear gloves, ear protection, and eye protection. Wrap a clean cloth around the air supply lines. The vehicle must be raised to perform this conversion! Use proper lifting equipment only! Read instructions carefully before attempting installation, if you have problems during the install then feel free to call our Technical Support Line. Please before calling for technical help, have your invoice handy.

  1. Remove the rear wheel. Torque: 103 Nm (76 ft. lbs.).
  2. Remove the rear seat cushion, rear seat back and package tray trim. Refer to body and schematic in Fig 1.
  3. Remove the rear drive shaft.
  4. Disconnect the stabilizer bar link from the stabilizer bar Fig 2. Torque: 65 Nm (48 ft. lbs.).
  5. Remove the rear brake caliper: Remove the 2 bolts and brake caliper. Torque: 104 Nm (77 ft. lbs.). Fig 3. Support the brake caliper securely.
  6. Remove ABS speed sensor. Remove the bolt and ABS speed sensor Fig 4. NOTICE: Do not disconnect the RH pad wear indicator connector. Torque: 7.8 Nm (69 inch lbs.)
  7. Disconnect height control sensor link from No. 1 lower suspension arm Fig 5.
    • Place the match marks on the link and bracket.
    • Remove the nut and disconnect the height control sensor link. Torque: 5.0 Nm (48 in. lbs.).
  8. Remove the shock absorber and coil spring.
  9. Loosen, but do NOT remove, the bolt and remove the nut on the lower side of the shock absorber Fig 6. Torque: 137 Nm (101 ft. lbs.).
  10. Support the rear axle carrier with a jack.
  11. Remove the 3 nuts and shock absorber cap Fig 7. Torque: 25 nm (18 ft. lbs.).
  12. Loosen, do NOT remove, the suspension support center nut. Torque to 27 Nm (20 ft. lbs.)
  13. Remove the 3 nuts. Torque to 64 Nm (47 ft. lbs.)
  14. Lower the rear axle carrier and remove the bolt on the lower side of the shock absorber Fig 8.
  15. Remove the air strut.

Rear Conversion Kit Installation InstructionsStep 2

  1. Install suspension support and temporarily tighten new nut, then rotate the suspension support until the rod and one suspension support bolt line up with the lower bushing Fig 9.
  2. Install the shock absorber in the vehicle with the three mounting nuts and torque to specifications Fig 10.
  3. Torque the suspension support to specification, then install shock absorber cap and three nuts.
  4. Connect shock absorber to rear axle carrier and temporarily install nut and bolt.
  5. Install the brake caliper and torque bolts to specifications.
  6. Connect both the stabilizer bar links and leave loose.
  7. Install the rear driveshaft.
  8. Install wheel and tire assembly, then lower the vehicle and bounce up and down several times to stabilize.
  9. Then tighten the lower strut bolt and the sway bar end links, this must be done while vehicle is on the tires.
  10. Torque the lower shock bolt to specifications.
  11. Should the vehicle still seem high, repeat jounce procedure.
  12. Install the package tray trim, right and left roof side inner garnishes, right and left rear scuff plates, rear seat back and rear seat cushion Fig 11.

Rear installation is now complete.

Note: The rear springs may settle some during the first couple of weeks of use. You may have to adjust the front height sensors to match the level of your new rear springs. The rear springs can sit a little low if your rear shocks are bad. Test the rear shocks by pushing down on the rear of the car. If the rear bounces then you need to replace the shocks also (Strutmasters carries replacement shocks if this is encountered).
When installation has been completed lower the vehicle off the lift. Recheck and tighten all nuts and bolts while the vehicle in on the ground. Read instructions carefully before attempting installation. Please, have invoice before calling.

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