Mercedes Coupes/Sedans/Wagons 1974-1984 Repair Guide

Lower Control Arm

Print

REMOVAL & INSTALLATION Except 190D, 190E, 1974-76 230, 240D, 280, 280C, 1975-76 300D, 380SL, 380SLC, 450SL and 450SLC Models



The lower control arm is the same as the front axle half. For safety install a spring compressor on the coil spring.

  1. Jack and support the front of the car and remove the wheels.
  2.  
  3. Remove the front shock absorber. Loosen the top mount first.
  4.  
  5. Remove the front springs.
  6.  
  7. Separate and plug the brake lines.
  8.  
  9. Remove the track rod from the steering knuckle arm.
  10.  
  11. Matchmark the position of the eccentric bolts on the bearing of the lower control arm in relation to the frame cross-member.
  12.  
  13. Remove the shield from the cross yoke.
  14.  
  15. Support the front axle half.
  16.  
  17. Loosen the eccentric bolt on the front and rear bearing of the lower control arm and knock them out.
  18.  
  19. Remove the bolt from the cross-yoke bearing.
  20.  
  21. Loosen the screw at the opposite end of the cross-yoke bearing.
  22.  
  23. Pull the cross-yoke bearing down slightly.
  24.  
  25. Loosen the support of the upper control arm on the torsion bar. Remove the clamp screw from the clamp.
  26.  
  27. Remove the upper control arm bearing on the front end.
  28.  
  29. Remove the front axle half.
  30.  
  31. Installation is the reverse of removal. Tighten the eccentric bolts of the lower control arm bearing with the car resting on the wheels. Bleed the brakes and check the front end alignment.
  32.  

190D and 190E Models See Figures 1, 2, 3 and 4

Click image to see an enlarged view

Fig. Fig. 1: Cross-sectional view of the front lower control arm bushing190 models



Click image to see an enlarged view

Fig. Fig. 2: Cross-sectional view of the rear lower control arm bushing190 models



Click image to see an enlarged view

Fig. Fig. 3: Caster angle affects straight line stability



Click image to see an enlarged view

Fig. Fig. 4: Camber angle influences tire contact with the road

  1. Remove the engine compartment lining at the bottom of the vehicle (if so equipped).
  2.  
  3. Raise the front of the vehicle and support it with jackstands. Remove the wheel.
  4.  
  5. Support the lower control arm with jackstands and then disconnect the torsion bar bearing at the control arm.
  6.  
  7. Remove the spring as detailed earlier in this section.
  8.  
  9. Disconnect the tie rod at the steering knuckle and then press out the ball joint with the proper tool.
  10.  
  11. Remove the brake caliper and position it out of the way. Be sure that you do not damage the brake line.
  12.  
  13. Remove the brake disc/wheel hub assembly.
  14.  
  15. Disconnect the lower end of the damper strut from the steering knuckle and then remove the knuckle.
  16.  
  17. Mark the position of the inner eccentric pins, relative to the frame, on the bearing of the control arm.
  18.  
  19. Unscrew and remove the pins.
  20.  
  21. Remove the jackstands and remove the lower control arm.
  22.  
  23. Installation is in the reverse order of removal. Please note the following:
    1. Tighten the eccentric bolts on the inner arm to 130 ft. lbs. (180 Nm).
    2.  
    3. To facilitate torsion bar installation, raise the opposite side of the lower control arm with a jack.
    4.  
    5. Tighten the clamp nut on the tie rod ball joint to 25 ft. lbs. (35 Nm).
    6.  

  24.  

1974-76 230, 240D, 280, 280C, 1975-76 300D, 380SL, 380SLC, 450SL and 450SLC Models

  1. Since the front shock absorber acts as a deflection stop for the front wheels, the lower shock absorber attaching point should not be loosened unless the vehicle is resting on the wheels or unless the lower control arm is supported.
  2.  
  3. Jack up the front of the vehicle and support it on jackstands.
  4.  
  5. Support the lower control arm.
  6.  
  7. Loosen the lower shock absorber attachment.
  8.  
  9. Unscrew the steering arm from the steering knuckle.
  10.  
  11. Separate the brake line and brake hose and plug the openings.
  12.  
  13. Remove the front spring.
  14.  
  15. Unscrew the hex nuts on the ball joints.
  16.  
  17. Remove the lower ball joint and remove the lower control arm.
  18.  
  19. Installation is the reverse of removal. Bleed the brakes and check the front end alignment.
  20.  

 
label.common.footer.alt.autozoneLogo