GM Cadillac 1967-1989 Repair Guide

MacPherson Struts

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The struts retain the springs under tremendous pressure, even when removed from the vehicle. For this reason, several expensive special tools and substantial specialized knowledge are required to safely and effectively work on these components. If spring and shock absorber work is required, it is a good idea to remove the strut involved yourself, then take it to a repair facility which is fully equipped and familiar with MacPherson struts.

REMOVAL & INSTALLATION



  1. Open the hood and remove the nuts attaching the top of the strut to the body.
  2.  
  3. Raise the vehicle and install jackstands under the cradle. Then, lower the vehicle so it rests on the jackstands and not on the control arms.
  4.  


CAUTION
Support all cars at the rear so that as components are removed, the weight will not shift, causing the car to fall off the supports.

  1. Remove the tire and wheels related to the strut(s) involved.
  2.  
  3. Using a sharp tool, scribe the knuckle along the lower outboard radius of the strut. Then, scribe the strut flange on the inboard side, right along the curve of the knuckle. Finally, make a scribe mark across the strut/knuckle interface. These scribe marks will be used on reassembly to properly match the components.
  4.  
  5. Remove the brake line mounting bracket from the strut.
  6.  


WARNING
When working near the drive axles, make sure you don't permit the inner tri-pot joints to become overextended, as this could cause undetectable damage. Also, make sure you do not scratch the spring coating, as this could result in premature failure of the spring.

  1. Remove the strut-to-knuckle nuts and bolts, then carefully support the knuckle from the body with wire.
  2.  
  3. Remove the strut.
  4.  

To install:
  1. Install the strut, aligning all scribe marks to ensure it is in the proper position. Install the strut-to-knuckle nuts and bolts, then tighten just slightly.
  2.  
  3. Install the brake line bracket back onto the strut.
  4.  
  5. Install the nuts attaching the top of the strut to the body. Now, torque those nuts to 18 ft. lbs. (24 Nm). Torque the strut-to-knuckle bolts/nuts to 145 ft. lbs. (196 Nm).
  6.  
  7. Install the wheel, and torque the nuts to 100 ft. lbs. (136 Nm). Lower the car.
  8.  

OVERHAUL



See Figures 1, 2, 3 and 4

There are five special tools that are required to complete this procedure, without them, strut overhaul is impossible. The tools are:

  1. J-3289-20 Holding fixture
  2.  
  3. J-34013-47 Template
  4.  
  5. J-34013-A Strut compressor
  6.  
  7. J-34013-20 Clamp
  8.  
  9. J-34013-38 Guiding rod
  10.  


WARNING
Care should be taken to avoid chipping or scratching the spring coating when handling the front suspension coil spring. Damage to the spring coating can cause premature spring failure.

  1. Mount the strut assembly into the strut compressor (J-34013-A). Turn the compressor forcing screw until the spring is slightly compressed.
  2.  
  3. Using a socket wrench, hold the dampener shaft from turning while you remove the nut at the top of the dampener shaft.
  4.  
  5. Using the guiding rod (J-34013-38), remove the dampener shaft from the strut assembly.
  6.  
  7. Loosen the compressor screw while sliding the dampener rod out of the strut assembly. Continue loosening the screw until the strut dampener and spring can be removed.
  8.  
  9. To install, position the strut dampener into the compressor with the clamp (J-34013-20) on the dampener shaft.
  10.  
  11. Position the spring over the strut in the correct manner, then move the assembly upright in the compressor and install the upper locking pin.
  12.  

The flat on the upper spring seat must face away from the centerline of the vehicle; or, when mounted in the compressor the spring seat will face the same direction as the steering knuckle mounting flange.

  1. Use the guiding rod once again and guide the dampener shaft into the strut body.
  2.  
  3. Turn the compressor screw clockwise while the guiding rod centers the shaft in the assembly.
  4.  
  5. Continue to turn the screw until the dampener shaft threads are visible through the top of the strut assembly, then install the washer and nut. Remove the clamp from the dampener shaft.
  6.  

Tighten the dampener shaft nut to 44 ft. lbs. (60 Nm) with a crowsfoot line wrench while holding the shaft with a socket wrench.

  1. Remove the three nuts mounting the strut assembly into the compressor, then the two locking pins at the bottom of the compressor. Remove the strut assembly.
  2.  



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Fig. Fig. 1: Mounting the strut in the compressor



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Fig. Fig. 2: Removing the damper shaft nut



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Fig. Fig. 3: Installing the dampener shaft guide rod



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Fig. Fig. 4: Installing the strut dampener in the compressor using the clamp

 
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