BMW Cars 1999-06

Strut (MacPherson Strut) Assembly

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Overhaul (Coil Spring Removal & Installation)




CAUTION
This procedure calls for the spring to be compressed using specially designed tools. A compressed spring has high potential energy and if released suddenly can cause severe damage and personal injury. If suitable tools and equipment are not available and safety compromised, have a professional technician remove the spring from the strut for you.

  1. Remove the strut from the vehicle and mount in a vise using a strut holder. This will prevent damage to the strut tube.
  2.  
  3. Using a suitable spring compressor, carefully compress the spring until the spring perch is no longer loaded by the spring. Use all the safety hooks provided and never point the compressed spring at a person.
  4.  
  5. Remove the top nut of the strut mount. Counterhold the strut rod during removal. If the special tool is not available, use a deep well socket to fit the strut rod locknut. Clamp a large pair of locking pliers onto the deep well socket, the use a socket with an extension placed through the opening in the deep well socket and using a ratchet, hold the strut dampening rod steady while removing the locknut.
  6.  
  7. With the locknut removed, pull the strut mount off the strut rod. Note the positioning of the spacers and washer for replacement.
  8.  
  9. Pull the spring off the strut and place somewhere safe. Do not release the compression of the spring.
  10.  


NOTE
On E36 models, the strut is replaced as an assembly. Compare the code just below the lower spring perch to make sure of the correct replacement or if replaced as a matched set, both codes should be identical.

  1. On E30 models:
    1. Remove the gland nut at the top of the strut housing. A special tool is sometimes needed to remove the nut. Some aftermarket strut manufacturers provide a tool with the replacement cartridges.
    2.  
    3. Pull the old cartridge out of the strut and pour out the oil.
    4.  

  2.  



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Fig. A cross-sectional view of a strut assembly with a renewable cartridge



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Fig. Cross sectional view of the spring and strut assembly-E30 models shown



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Fig. Use a good quality spring compressor to collapse the spring, then remove the shock dampening rod locknut



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Fig. Once the locknut is removed, the washer, bearing/mount assembly, washer, top spring perch and rubber ring can be removed



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Fig. In order of installation after the spring: the bump stop/boot, rubber ring, top spring perch, washer, strut bearing/mount assembly, washer and locknut



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Fig. Make sure the lower spring perch pad is properly seated before installing the spring

To install:

  1. On E30 models:
    1. Fill the strut tube with enough engine oil or ATF so when the new cartridge is installed, oil fills the tube but doesn't overflow. If the strut rod diameter is greater than 1.299 in. (33mm) do not use oil.
    2.  
    3. Install the new cartridge and any spacers that where provided by the manufacturer. Install the gland nut and tighten to 94 ft. lbs. (130 Nm).
    4.  

  2.  
  3. If replacing the spring, carefully remove the spring compressor and install the compressor on the new spring and carefully compress.
  4.  
  5. If necessary, transfer the rubber spring seats to the replacement strut.
  6.  
  7. Inspect the spring mount cushion and bearing condition and replace if the cushion is cracking or collapsed or if the bearing does not move smoothly.
  8.  
  9. Install the spring and strut mount with all the spacers, boots or cushions and washers in their original positions. Tighten the new strut rod locknut as follows:

    Dampening rods with external hexagon: 47 ft. lbs. (64 Nm)
     
    Dampening rods with internal hexagon: 32 ft. lbs. (44 Nm)
     

  10.  
  11. Release the spring slowly and check that it seats in the spring holders. Install the strut in the vehicle.
  12.  


CAUTION
This procedure calls for the spring to be compressed. A compressed spring has high potential energy and if released suddenly can cause severe damage and personal injury.

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove the strut from the vehicle and mount in a vise using a strut holder. This will prevent damage to the strut tube.
  4.  
  5. Using a proper spring compressor, compress the spring and lock into place.
  6.  
  7. Remove the top nut of the strut mount. Counterhold the strut rod during removal.
  8.  
  9. Pull the strut mount off the strut rod. Note the positioning of the spacers and washer for replacement.
  10.  
  11. Pull the spring off the strut and place aside in a safe area.
  12.  
  13. Slowly release the compression of the spring.
  14.  

To install:

  1. Install the spring in the compressor and compress.
  2.  
  3. Install the spring and strut mount with all the spacers and washers in their original positions. New strut rod nut: 47 ft. lbs. (65 Nm).
  4.  
  5. Release the spring slowly and check that it seats in the spring holders. Install the strut in the vehicle.

    Click image to see an enlarged view

    Fig. Cut away view of the strut mount and related components-3-Series models



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    Fig. Cut away view of the strut mounting with a separate support bearing and related components-3-Series models



    Click image to see an enlarged view

    Fig. Cut away view of the strut mount and related components-5 and 7-Series

  6.  

Removal & Installation



  1. Disconnect the negative battery cable.
  2.  
  3. Raise and safely support the vehicle. Remove the tire and wheel assembly.
  4.  
  5. Disconnect the brake pad wear indicator plug and ground wire. Pull the wires out of the holder on the strut. Remove the ABS pulse sender, if equipped.
  6.  
  7. Disconnect the stabilizer pushrod with the proper tool.
  8.  
  9. Disconnect the lower strut bolts at the control arm.
  10.  
  11. Support the bottom of the strut and unscrew the nuts at the top of the strut, from inside the engine compartment. Remove the strut.
  12.  
  13. The installation is the reverse of the removal procedure.
  14.  

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Tire and wheel assembly
     
    Brake pad wear indicator plug and ground wire
     
    Wires out of the holder on the strut
     
    ABS pulse sender, if equipped
     
    Caliper and pull it away from the strut, suspending it from the body. Do not disconnect the brake line.
     
    Attaching nut, then detach the pushrod on the stabilizer bar at the strut
     
    Attaching nut and press off the guide joint with the proper tool
     
    Nut and press off the tie rod joint
     

  4.  
  5. Press the bottom of the strut outward and push it over the guide joint pin, using the proper tool. Support the bottom of the strut.
  6.  
  7. Remove the nuts at the top of the strut, from inside the engine compartment, then remove the strut.
  8.  

To install:

  1. Position the strut in the vehicle. Upper strut mounting nuts: 16-17 ft. lbs. (21-23 Nm). The upper strut mounting nuts must be replaced with new self-locking nuts.
  2.  
  3. The remaining components are installed in the reverse order from which they were removed. Tie rod and guide joints must have both pins and bores clean for reassembly. Replace both self-locking nuts. Tighten the control arm to spring strut attaching nut to 43-51 ft. lbs. (59-69 Nm).
  4.  
  5. Install the front tire and wheel assemblies.
  6.  
  7. Connect the negative battery cable.
  8.  

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Tire and wheel assembly
     
    Brake pad wear indicator plug and ground wire
     
    Wires out of the holder on the strut
     
    ABS pulse sender, if equipped
     
    Stabilizer pushrod with the proper tool
     
    Lower strut bolts at the control arm
     

  4.  
  5. Support the bottom of the strut and remove the nuts at the top of the strut, from inside the engine compartment. Remove the strut.

    Click image to see an enlarged view

    Fig. 5 Series front suspension and steering components

  6.  

To install:

  1. The installation is the reverse of the removal procedure.
  2.  

E30 Models
320 Ix Models
  1. Disconnect the negative battery cable.
  2.  
  3. Raise and safely support the vehicle. Remove the front tire and wheel assembly. Unplug the ABS pulse transmitter.
  4.  
  5. Lift out the lock plate at the center of the brake disc with a small prybar. Unscrew the collar nut.
  6.  
  7. Disconnect the brake pad wear indicator plug and the ground wire. Pull the wires and brake hose out of the clip on the spring strut. Then, disconnect the small rod at the strut.
  8.  
  9. Remove the brake caliper mounting bolts and support the assembly with a piece of wire, keeping stress off the brake hose.
  10.  
  11. Remove the attaching nut from the tie rod end. Then press the stud off the knuckle with the proper tool.
  12.  


NOTE
Do not turn the steering rack to full lock or damage to the seals can occur.

  1. Remove the attaching nut for ball joint and then press the stud off the knuckle with an appropriate tool.
  2.  
  3. Press the output shaft out of the center of the knuckle.
  4.  
  5. Support the spring strut from underneath. Remove the 3 bolts from the upper mount at the wheel housing. Remove the strut.
  6.  

To install:

  1. Install the strut into the wheel housing and install the nuts. Press down on the control arm and install the ball joint stud into the strut bore. Using new nuts, tighten the ball joint to 61 ft. lbs. (85 Nm) and the top strut mounting nuts to 16-17 ft. lbs. (21-23 Nm).
  2.  
  3. Pull the axle through the bearing. Install a new nut and tighten to 180 ft. lbs. (250 Nm). Install a new lockplate.
  4.  
  5. Install the tie rod into the steering arm and tighten the new nut to 26 ft. lbs. (37 Nm).
  6.  
  7. Install the stabilizer bar link and tighten to 43 ft. lbs. (59 Nm).
  8.  
  9. Install the brake caliper and tighten to 80 ft. lbs. (110 Nm).
  10.  
  11. Install the ABS sensor, the brake pad wear sensor and the brake hose. Connect the negative battery terminal. Have the alignment checked.
  12.  

Except 320 Ix Models
  1. Disconnect the negative battery cable.
  2.  
  3. Raise and safely support the vehicle. Remove the tire and wheel assembly.
  4.  
  5. Disconnect the brake pad wear indicator plug and ground wire. Pull the wires out of the holder on the strut. Remove the ABS pulse sender, if equipped.
  6.  
  7. Unbolt the caliper and pull it away from the strut, suspending it with a piece of wire from the body. Do not disconnect the brake line.
  8.  
  9. Remove the attaching nut and then detach the push rod on the stabilizer bar at the strut.
  10.  
  11. Unscrew the attaching nut and press off the ball joint stud with the proper tool.
  12.  
  13. Unscrew the nut and press off the tie rod joint.
  14.  


NOTE
Do not turn the steering rack to full lock or damage to the seals can occur.

  1. Press the bottom of the strut outward and push it over the ball joint stud. Support the bottom of the strut.
  2.  
  3. Unscrew the nuts at the top of the strut, from inside the engine compartment, then remove the strut.
  4.  

To install:

  1. Install the strut into the wheel housing and install the nuts. Press down on the control arm and install the ball joint stud into the strut bore. Using new nuts, tighten the ball joint to 61 ft. lbs. (85 Nm) and the top strut mounting nuts to 16-17 ft. lbs. (21-23 Nm).
  2.  
  3. Install the tie rod into the steering arm and tighten the new nut to 26 ft. lbs. (37 Nm).
  4.  
  5. Install the stabilizer bar link and tighten to 43 ft. lbs. (59 Nm).
  6.  
  7. Install the brake caliper and tighten to 80 ft. lbs. (110 Nm).
  8.  
  9. Install the ABS sensor, the brake pad wear sensor and the brake hose. Connect the negative battery terminal. Have the alignment checked.
  10.  

E36 Models
  1. Raise and safely support the vehicle.
  2.  
  3. Remove the wheel assembly. Disconnect the brake line and the wires from the holders on the strut, but do not disconnect from the caliper.
  4.  
  5. If installed, disconnect the stabilizer bar link from the strut.
  6.  
  7. Remove the two lower strut-to-steering knuckle bolts using a six point 1 / 2 inch drive socket and a sturdy breaker bar. Typically the bolt heads are an 18mm. The bolts are secured with a locking agent and require significant leverage to break loose. Do not use an air tool to break these loose, as the fastener may snap.
  8.  
  9. Remove the upper through bolt and locknut holding the steering knuckle assembly to the strut.
  10.  
  11. Matchmark the forward stud, then while supporting the strut, remove the 3 mounting nuts at the top of the strut assembly and carefully lower and remove the strut from the vehicle.
  12.  



Click image to see an enlarged view

Fig. Remove the hydraulic brake line and if equipped, the ABS sensor wire from the mounting brackets on the strut



Click image to see an enlarged view

Fig. The two lower strut bolts have a locking agent on them. Use a sturdy 1/2 inch drive 6 point socket and breaker bar to loosen



Click image to see an enlarged view

Fig. Remove the upper through bolt and the two lower strut-to-knuckle bolts, then remove the strut from the steering knuckle



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Fig. The two lower strut-to-knuckle bolts have a locking agent on them. Make sure to clean them and reapply a locking agent to the threads during assembly



Click image to see an enlarged view

Fig. Matchmark the upper strut mount to ease reassembly

To install:

  1. Install the strut into the inner fender strut tower and tighten the new mounting nuts to 16-17 ft. lbs. (21-23 Nm).
  2.  
  3. Clean the threaded holes in the steering knuckle and guide the strut onto the steering knuckle. Apply a locking agent to the new micro-encapsulated strut-to-knuckle mounting bolts and tighten to 60 ft. lbs. (81 Nm).
  4.  
  5. If removed, install the stabilizer bar link and tighten to 43 ft. lbs. (59 Nm).
  6.  
  7. Install the brake hose and wires into the holders.
  8.  
  9. Install the wheel and tire assembly, then carefully lower the vehicle.
  10.  
  11. Have the alignment checked.
  12.  

 
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