CTS 2003-2005

Strut (MacPherson Strut)

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Disassembly & Assembly



Spring Replacment

NOTE
To disassemble the strut for spring replacement, special compressor tools are required to relieve the tension on the top retaining nut. GM recommends their tool set. In your locality, it may be possible to rent a similar tool. Another possibility is to take the strut and spring assembly to a qualified shop with the proper equipment to have the strut disassembled for either spring or strut replacement. The replacement part can then be swapped out and the shop may be able to reassemble the strut for a modest price.

  1. Remove the strut from the vehicle using the procedures found in this section.
  2.  
  3. Mount the strut in a strut compressor tool.
  4.  
  5. Use the strut compressor forcing screw to compress the spring just enough to release the tension from the strut mount.
  6.  
  7. Remove the strut shaft nut.
  8.  
  9. Relieve the spring tension and remove the spring from the strut.
  10.  



Click image to see an enlarged view

Fig. Typical strut compressor tools recommended by GM for W-Body front strut disassembly

To install:

  1. Inspect all components for wear or damage.
  2.  
  3. Install the rear spring lower insulator. Make sure the lower spring is visible between the step and the location mark on the insulator.
  4.  
  5. Install the rear suspension spring and the dust shield to the lower insulator. Install the jounce bumper and strut mount.
  6.  
  7. Use a strut compressor to compress the strut, working the strut shaft through the strut mount.
  8.  
  9. Compress the strut and spring assembly enough to install the strut shaft nut. Torque the nut to 55 ft. lbs. (75 Nm).
  10.  
  11. Install the strut into the vehicle using the procedures found in this section.
  12.  

Precautions



The front suspension struts (in previous years, sometimes called MacPherson Struts) combine the functions of a shock absorber (damper) and a spring mount into one structural assembly, a major component of the front suspension and steering systems. While removing the strut assembly is straightforward, disassembling the strut for spring removal and/or strut replacement requires special tools. Older vehicles had struts that could be taken apart and overhauled. The struts on vehicles covered by this manual do not come apart, except for the coil spring which can be replaced. If special tools are not available to disassemble the strut, it may be possible to purchase an aftermarket spring and strut already assembled.

Removal & Installation




WARNING
Use care when servicing the front strut to avoid chipping or scratching the coating on the coil spring. Damage to the coating can cause premature failure.

  1. Under the hood, locate and remove the three strut-to-body mount nuts.
  2.  
  3. Raise and safely support the vehicle. Allow the control arms to hang free.
  4.  
  5. Remove the wheel and tire assembly.
  6.  
  7. Scribe a mark around the strut bracket to the knuckle. This will help align the strut at assembly.
  8.  


WARNING
When the strut-to-knuckle bolts are removed, the knuckle will drop and possibly overextend and damage the halfshaft. The ball joint could also be damaged. Support or otherwise restraint the knuckle.

  1. Remove the two strut-to-knuckle bolts.
  2.  
  3. Remove the strut from the vehicle.
  4.  



Click image to see an enlarged view

Fig. Exploded view of the front strut removal

To install:

  1. Install the strut and spring assembly into place taking care to align any scribe marks made at removal.
  2.  
  3. Install three strut-to-body mount nuts and tighten to 30 ft. lbs. (41 Nm).
  4.  
  5. Install the two strut-to-knuckle bolts and tighten to 90 ft. lbs. (123 Nm).
  6.  
  7. Install the tire and wheel assembly.
  8.  
  9. Lower the vehicle.
  10.  
  11. Take the vehicle to a reputable repair shop to have an alignment performed. A vehicle alignment is mandatory after strut replacement.
  12.  

 
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