Home ReviewsRefund
Home/Cadillac/ELR/Cadillac ELR I (2013-2015)/Repair manual/Suspension Front/Front Suspension System
Contents Wiring diagrams Section: Suspension Front All sections

Front Suspension System Cadillac ELR I

Suspension Front 11 illustrations ~2246 words

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
Front Lower Control Arm Front Bolt (1)
First Pass70 N.m52 lb ft
Final Pass75-90 Degrees
Front Lower Control Arm Rear Bolt (1)
First Pass70 N.m52 lb ft
Final Pass75-90 Degrees
Front Lower Control Arm Rear Bushing Bolt
First Pass55 N.m41 lb ft
Final Pass90-105 Degrees
Front Stabilizer Shaft Insulator Clamp Bolt (1)
First Pass22 N.m16 lb ft
Final Pass30-45 Degrees
Front Stabilizer Shaft Link Nut65 N.m48 lb ft
Front Suspension Strut Mount Nut65 N.m48 lb ft
Front Suspension Strut Nut70 N.m52 lb ft
Front Suspension Strut Yoke Nut70 N.m52 lb ft
Front Wheel Bearing and Hub Assembly Bolt
First Pass100 N.m74 lb ft
Final Pass15-30 Degrees
Steering Knuckle Camber Adjust Nut (Lower Nut) (1)
First Pass115 N.m85 lb ft
Final Pass120-135 Degrees
Steering Knuckle Camber Adjust Nut (Upper Nut)
First Pass70 N.m52 lb ft
Final Pass45-60 Degrees
Steering Knuckle King Pin Bushing Nut70 N.m52 lb ft
Steering Knuckle Nut (at Front Lower Control Arm) (1)
First Pass115 N.m85 lb ft
Final Pass120-135 Degrees
Steering Knuckle Nut (at Front Suspension Strut Yoke Upper Ball Joint)
First Pass45 N.m33 lb ft
Second Pass45 Degrees
Final Pass15 Degrees
1. Torque-to-yield fastener in use, requires NEW bolt.

Fastener Tightening Specifications

Scheme 4

Scheme 4: Stabilizer Shaft Replacement
Scheme 4: Stabilizer Shaft Replacement
CalloutComponent Name
Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle . Remove the front tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation . Disconnect the front stabilizer shaft links from the front stabilizer shaft. Refer to Stabilizer Shaft Link Replacement . Lower the rear of the drivetrain and front suspension frame to gain the necessary clearance to remove the front stabilizer shaft. Refer to Drivetrain and Front Suspension Frame Replacement .
1Front Stabilizer Shaft Insulator Clamp Bolt (Qty: 4) CAUTION: Refer to Fastener Caution . CAUTION: This vehicle is equipped with torque-to-yield or single use fasteners. Install a NEW torque-to-yield or single use fastener when installing this component. Failure to replace the torque-to-yield or single use fastener could cause damage to the vehicle or component. Procedure Remove and DISCARD the bolts. Do not reuse, replace with NEW only. Tighten 22 N.m (16 lb ft) + 30-45 degrees
2Front Stabilizer Shaft Procedure Transfer components as necessary.
CAUTION
Refer to Fastener Caution .
CAUTION
This vehicle is equipped with torque-to-yield or single use fasteners. Install a NEW torque-to-yield or single use fastener when installing this component. Failure to replace the torque-to-yield or single use fastener could cause damage to the vehicle or component.

Stabilizer Shaft Replacement

Scheme 5

Scheme 5: Stabilizer Shaft Link Replacement
Scheme 5: Stabilizer Shaft Link Replacement
CalloutComponent Name
Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle . Remove the front tire and wheel assembly. Refer to Tire and Wheel Removal and Installation . Disconnect any harnesses or retainers secured to the front stabilizer shaft link. Note any attaching points to aid in installation.
1Front Stabilizer Shaft Link Nut (Qty: 2) CAUTION: Refer to Fastener Caution . Tighten 65 N.m (48 lb ft)
2Front Stabilizer Shaft Link
CAUTION
Refer to Fastener Caution .

Stabilizer Shaft Link Replacement

Scheme 6

Scheme 6: Front Wheel Bearing and Hub Replacement
Scheme 6: Front Wheel Bearing and Hub Replacement
CalloutComponent Name
Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle . Remove the front suspension strut yoke. Refer to Front Suspension Strut Yoke Replacement .
1Front Wheel Bearing and Hub Assembly Bolt (Qty: 3) CAUTION: Refer to Fastener Caution . Tighten 100 N.m (74 lb ft) + 15-30 degrees
2Front Brake Shield
3Front Wheel Bearing and Hub Assembly
CAUTION
Refer to Fastener Caution .

Front Wheel Bearing and Hub Replacement

Removal Procedure

  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/elr/i-2013-2015/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  2. Remove the front suspension strut yoke. Refer to «Front Suspension Strut Yoke Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .
  3. Remove the front wheel bearing and hub assembly. Refer to «Front Wheel Bearing and Hub Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .
  4. Loosen the steering knuckle king pin bushing nuts (1) until they are even with the steering knuckle king pin bushing studs or two or three threads of each nut are exposed.
  5. Use a hammer and brass punch to drive both of the steering knuckle king pin bushing studs partially inward to release the knurls from the steering knuckle king pin bushing.
  6. Completely remove the steering knuckle king pin bushing nuts.
  7. Disconnect the front suspension strut yoke upper ball joint from the steering knuckle. Refer to «Front Suspension Strut Yoke Upper Ball Joint Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .
  8. Remove the steering knuckle (1) from the front suspension strut yoke.

Installation Procedure

  1. Position the steering knuckle (1) in the front suspension strut yoke.
  2. Connect the front suspension strut yoke upper ball joint to the steering knuckle. Refer to «Front Suspension Strut Yoke Upper Ball Joint Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .
  3. Tighten the steering knuckle king pin bushing nuts (1) in small, equal increments to 70 N.m (52 lb ft).
  4. Install the front wheel bearing and hub assembly. Refer to «Front Wheel Bearing and Hub Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .
  5. Install the front suspension strut yoke. Refer to «Front Suspension Strut Yoke Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .
  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/elr/i-2013-2015/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  2. Remove the front tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/elr/i-2013-2015/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
  3. Remove the front lower control arm rear nuts (1) and bolts (2). DISCARD the bolts.
  4. Remove the steering knuckle nut (3) and bolt (1). DISCARD the bolt.
  5. Remove the front lower control arm front nut (4) and bolt (5). DISCARD the bolt.
  6. Remove the front lower control arm (2) from the vehicle.
  7. Transfer components as necessary.
  1. Position the front lower control arm (2) on the vehicle.
  2. Install the NEW front lower control arm front bolt (5) and OLD nut (4) and tighten the bolt to 70 N.m (52 lb ft) + 75-90 degrees.
  3. Install the NEW steering knuckle bolt (1) and OLD nut (3) and tighten the nut to 115 N.m (85 lb ft) + 120-135 degrees.
  4. Install the NEW front lower control arm rear bolts (2) and OLD nuts (1) and tighten the bolts to 70 N.m (52 lb ft) + 75-90 degrees.
  5. Install the front tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/elr/i-2013-2015/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .

Scheme 7

Scheme 7: Front Lower Control Arm Rear Bushing Replacement
Scheme 7: Front Lower Control Arm Rear Bushing Replacement
CalloutComponent Name
Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle . Remove the front lower control arm. Refer to Lower Control Arm Replacement .
1Front Lower Control Arm Rear Bushing Bolt CAUTION: Refer to Fastener Caution . NOTE: Tighten the bolt with the vehicle at ride height. Tighten 55 N.m (41 lb ft) + 90-105 degrees
2Front Lower Control Arm Rear Bushing
CAUTION
Refer to Fastener Caution .
NOTE
Tighten the bolt with the vehicle at ride height.

Front Lower Control Arm Rear Bushing Replacement

Wheel Stud Replacement

Special Tools

CH-43631 Ball Joint Separator

For equivalent regional tools, refer to Special Tools .

  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/elr/i-2013-2015/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  2. Remove the front wheel bearing and hub assembly. Refer to «Front Wheel Bearing and Hub Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .
  3. Use the CH-43631 separator (1) to remove the wheel stud (2) from the front wheel bearing and hub assembly. DISCARD the stud.
  1. Position the NEW wheel stud (1) in the front wheel bearing and hub assembly.
  2. Install flat washers (2) and an OLD wheel nut (3) on the wheel stud.
  3. Use a suitable tool to prevent the flange on the front wheel bearing and hub assembly from turning.
  4. Tighten the wheel nut until the wheel stud is firmly seated.
  5. Remove the wheel nut and flat washers.
  6. Install the front wheel bearing and hub assembly. Refer to «Front Wheel Bearing and Hub Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .

Strut and Shock Absorber Inspection

Note. The strut assembly DOES NOT have to be removed from the vehicle to perform the following inspection procedure.

Note. A light film of oil on the top portion of the strut is normal. DO NOT replace the strut for this condition.

Scheme 8

Scheme 8: Strut and Shock Absorber Inspection
Scheme 8: Strut and Shock Absorber Inspection

Condition 1

Oil or fluid residue only on the bottom of the strut tube or on other strut components and not originating from the shaft seal, is not a strut related problem. DO NOT replace the strut, look for other external leaks.

Condition 2

Light film/residue on the strut tube, but not on the spring seat and originating from the shaft seal, is a NORMAL condition. DO NOT replace the strut.

Condition 3

Oil drip or trail down the strut tube and originating from the shaft seal, is an ABNORMAL condition. Replace the strut.

Condition 4

Extreme wet film of oil covering the strut tube and pooling in the spring seat and originating from the shaft seal, is an ABNORMAL condition. Replace the strut.

Inspection

  1. Verify the customer's concern is present. If the concern is present, continue to the next step. If the concern is not present, then the vehicle is operating normally.
  2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/elr/i-2013-2015/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  3. Visually inspect each of the shock absorbers or struts for external fluid leaks. Refer to the following conditions 1, 2 , 3 , and 4 for visual inspection. If conditions 1 or 2 are found, continue to step 4. If conditions 3 or 4 are found, replace strut. Refer to Strut Replacement.
  4. If equipped with electronic suspension control system, ensure that the system is working properly. Refer to Diagnostic Starting Point-Electronic Suspension Control.
  5. Use your hands in order to lift up and push down on each corner of the vehicle 3 times. Remove your hands from the vehicle. If the corner motion exceeds 2 cycles, replace the strut. If the strut does not exceed 2 cycles, NO repair is necessary.

Strut Assembly Removal and Installation

Special Tools

CH-49375 Spanner

For equivalent regional tools, refer to Special Tools .

  1. Remove the front tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/elr/i-2013-2015/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
  2. Disconnect the front wheel drive shaft from the steering knuckle. Refer to «Front Wheel Drive Shaft Replacement - Left Side»(/cadillac/elr/i-2013-2015/remont/axle-shafts/#wheel-drive-shafts__front-wheel-drive-shaft-replacement) , or «Front Wheel Drive Shaft Replacement - Right Side»(/cadillac/elr/i-2013-2015/remont/axle-shafts/#wheel-drive-shafts__front-wheel-drive-shaft-replacement) .
  3. Remove the front brake rotor. Refer to «Front Brake Rotor Replacement»(/cadillac/elr/i-2013-2015/remont/mechanical-hydraulic/#disc-brake-system__front-brake-rotor-replacement) .
  4. Disconnect the steering linkage outer tie rod from the steering knuckle. Refer to «Steering Linkage Outer Tie Rod Replacement»(/cadillac/elr/i-2013-2015/remont/manual-power-steering/#power-steering-system) .
  5. Disconnect the front stabilizer shaft link from the strut assembly. Refer to «Stabilizer Shaft Link Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .
  6. Remove the front brake hose from the bracket on the strut assembly.
  7. Remove the front wheel speed sensor from the steering knuckle. Refer to «Front Wheel Speed Sensor Replacement»(/cadillac/elr/i-2013-2015/remont/anti-locktraction-control/#antilock-brake-system) .
  8. Disconnect the front lower control arm from the steering knuckle. Refer to «Lower Control Arm Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .
  9. Remove the air inlet grille panel. Refer to «Air Inlet Grille Panel Replacement»(/cadillac/elr/i-2013-2015/remont/wiperwasher-systems/#wiper-system-and-washer-system) .
  10. Use the CH-49375 spanner and a suitable tool to remove the front suspension strut mount nut (1).
  11. Remove the front suspension strut bumper stop (2).
  12. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/elr/i-2013-2015/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  13. Remove the strut assembly (1) and front suspension strut yoke from the vehicle.
  14. Remove the front suspension strut yoke nut (1) and bracket (2).
  15. Remove the front suspension strut yoke bolt (3).
  16. Separate the strut assembly (4) from the front suspension strut yoke.
  17. Transfer components as necessary.
  1. Install the strut assembly (4) in the front suspension strut yoke.
  2. Install the front suspension strut yoke bolt (3) and bracket (2).
  3. Install the front suspension strut yoke nut (1) and tighten to 70 (52 lb ft).
  4. Install the strut assembly (1) and front suspension strut yoke on the vehicle.
  5. Lower the vehicle and position the front suspension strut bumper stop (2) on the strut assembly tower.
  6. Start the front suspension strut mount nut (1) by hand but do not tighten to specification.
  7. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/elr/i-2013-2015/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  8. Connect the front lower control arm to the steering knuckle. Refer to «Lower Control Arm Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .
  9. Install the front wheel speed sensor in the steering knuckle. Refer to «Front Wheel Speed Sensor Replacement»(/cadillac/elr/i-2013-2015/remont/anti-locktraction-control/#antilock-brake-system) .
  10. Install the front brake rotor. Refer to «Front Brake Rotor Replacement»(/cadillac/elr/i-2013-2015/remont/mechanical-hydraulic/#disc-brake-system__front-brake-rotor-replacement) .
  11. Install the front brake hose in the bracket on the strut assembly.
  12. Connect the front stabilizer shaft link to the strut assembly. Refer to «Stabilizer Shaft Link Replacement»(/cadillac/elr/i-2013-2015/remont/suspension-front/#front-suspension-system) .
  13. Connect the steering linkage outer tie rod to the steering knuckle. Refer to «Steering Linkage Outer Tie Rod Replacement»(/cadillac/elr/i-2013-2015/remont/manual-power-steering/#power-steering-system) .
  14. Connect the front wheel drive shaft to the steering knuckle. Refer to «Front Wheel Drive Shaft Replacement - Left Side»(/cadillac/elr/i-2013-2015/remont/axle-shafts/#wheel-drive-shafts__front-wheel-drive-shaft-replacement) , or «Front Wheel Drive Shaft Replacement - Right Side»(/cadillac/elr/i-2013-2015/remont/axle-shafts/#wheel-drive-shafts__front-wheel-drive-shaft-replacement) .
  15. Install the front tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/elr/i-2013-2015/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
  16. Lower the vehicle until the vehicle is resting fully on the ground.
  17. Use the CH-49375 spanner and a suitable tool to install the front suspension strut mount nut (1) and tighten to 65 (48 lb ft).
  18. Install the air inlet grille panel. Refer to «Air Inlet Grille Panel Replacement»(/cadillac/elr/i-2013-2015/remont/wiperwasher-systems/#wiper-system-and-washer-system) .
  19. Measure and adjust the front wheel alignment specifications. Refer to «Wheel Alignment Specifications»(/cadillac/elr/i-2013-2015/remont/wheel-alignment/#wheel-alignment-system__wheel-alignment-specifications) .

Scheme 9

Scheme 9: Front Suspension Strut Yoke Replacement
Scheme 9: Front Suspension Strut Yoke Replacement
CalloutComponent Name
Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle . Remove the front tire and wheel assembly. Refer to Tire and Wheel Removal and Installation . Disconnect the steering linkage outer tie rod from the steering knuckle. Refer to Steering Linkage Outer Tie Rod Replacement . Disconnect the front wheel drive shaft from the front wheel bearing and hub assembly. Refer to Front Wheel Drive Shaft Replacement - Left Side , or Front Wheel Drive Shaft Replacement - Right Side . Remove the front brake rotor. Refer to Front Brake Rotor Replacement . Remove the front wheel speed sensor from the steering knuckle. Refer to Front Wheel Speed Sensor Replacement .
1Front Suspension Strut Yoke Procedure Disconnect the front lower control arm from the front suspension strut yoke. Refer to Lower Control Arm Replacement . Disconnect the strut assembly from the front suspension strut yoke. Refer to Strut Assembly Removal and Installation . Transfer components as necessary. NOTE: Note the orientation of the bracket on the front suspension strut yoke before removal to aid in installation.
NOTE
Note the orientation of the bracket on the front suspension strut yoke before removal to aid in installation.

Front Suspension Strut Yoke Replacement

Scheme 10

Scheme 10: Front Suspension Strut Yoke Upper Ball Joint Replacement
Scheme 10: Front Suspension Strut Yoke Upper Ball Joint Replacement
CalloutComponent Name
Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle . Remove the front suspension strut yoke. Refer to Front Suspension Strut Yoke Replacement .
1Steering Knuckle Camber Adjust Nut (Qty: 2) CAUTION: Refer to Fastener Caution . NOTE: The steering knuckle camber adjust nuts are two different sizes. Note the position of the nuts prior to removing or replacing them. Do not completely tighten the steering knuckle camber adjust nuts during installation. Tighten the nuts to specification after the front suspension alignment is completed. Tighten Upper Steering Knuckle Camber Adjust Nut to 70 (52 lb ft) + 45-60 degrees Lower Steering Knuckle Camber Adjust Nut to 115 (85 lb ft) + 120-135 degrees
2Steering Knuckle Camber Adjust Washer
3Steering Knuckle Camber Adjust Bolt (Upper)
4Steering Knuckle Camber Adjust Bolt (Lower) CAUTION: This vehicle is equipped with torque-to-yield or single use fasteners. Install a NEW torque-to-yield or single use fastener when installing this component. Failure to replace the torque-to-yield or single use fastener could cause damage to the vehicle or component. Procedure Remove and DISCARD the bolt. Do not reuse, replace with NEW only.
5Steering Knuckle Nut Tighten First Pass: 45 N.m (33 lb ft) Second Pass: 45 degrees Final Pass: 15 degrees
6Front Suspension Strut Yoke Upper Ball Joint Procedure Use the CH-43631 separator to separate the front suspension strut yoke upper ball joint and the steering knuckle. Align the front suspension. Refer to Wheel Alignment Specifications . Special Tools CH-43631 Ball Joint Separator For equivalent regional tools, refer to Special Tools .
CAUTION
Refer to Fastener Caution .
NOTE
The steering knuckle camber adjust nuts are two different sizes. Note the position of the nuts prior to removing or replacing them. Do not completely tighten the steering knuckle camber adjust nuts during installation. Tighten the nuts to specification after the front suspension alignment is completed.
CAUTION
This vehicle is equipped with torque-to-yield or single use fasteners. Install a NEW torque-to-yield or single use fastener when installing this component. Failure to replace the torque-to-yield or single use fastener could cause damage to the vehicle or component.

Front Suspension Strut Yoke Upper Ball Joint Replacement

Suspension Shock/Strut Disposal

  1. Clamp the strut in a vise horizontally with the rod (1) completely extended.
  2. Drill a hole in the strut at the center of the end cap (3) using a 5 mm (3/16 in) drill bit. Gas or a gas/oil mixture will exhaust when the drill bit penetrates the strut. Use shop towels in order to contain the escaping oil.
  3. Remove the strut from the vise.
  4. Hold the strut over a drain pan vertically with the hole down.
  5. Move the rod (1) in and out of the tube (2) to completely drain the oil from the strut.

Scheme 11

Scheme 11: Strut, Strut Component, or Spring Replacement
Scheme 11: Strut, Strut Component, or Spring Replacement
CalloutComponent Name
WARNING: To prevent personal injury and/or component damage, use the proper tools to support and compress the coil spring prior to removal of the strut shaft nut when removing the coil spring. The coil spring is under extreme pressure and can become a projectile should the spring separate from the strut before all of the tension is relieved. Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle . Remove the strut assembly. Refer to Strut Assembly Removal and Installation .
1Front Suspension Strut Nut CAUTION: Refer to Fastener Caution . Procedure Use the CH-48845 compressor to compress the front strut assembly. Use the CH-49375 spanner and a suitable tool to remove the front suspension strut nut. Tighten 70 (52 lb ft) Special Tool CH-48845 Strut Spring Compressor CH-49375 Spanner For equivalent regional tools, refer to Special Tools .
2Front Suspension Strut Mount Washer
3Front Suspension Strut Mount
4Front Coil Spring Upper Insulator
5Front Coil Spring
6Front Shock Absorber Boot
7Front Suspension Strut Bumper Inspect the front suspension strut bumper for the following: Cracks or structural damage Wetness from oil contamination Loose fit to strut rod or excessive play from damage to the inner diameter retention fingers If any issues are noted, replace the front suspension strut bumper.
8Front Coil Spring Lower Insulator
9Front Suspension Strut
WARNING
To prevent personal injury and/or component damage, use the proper tools to support and compress the coil spring prior to removal of the strut shaft nut when removing the coil spring. The coil spring is under extreme pressure and can become a projectile should the spring separate from the strut before all of the tension is relieved.
CAUTION
Refer to Fastener Caution .

Strut, Strut Component, or Spring Replacement

Front Suspension Description and Operation

The front suspension has 2 primary purposes

  1. Isolate the driver from irregularities in the road surface.
  2. Define the ride and handling characteristics of the vehicle.

The front suspension absorbs the impact of the tires travelling over irregular road surfaces and dissipates this energy throughout the suspension system. This process isolates the vehicle occupants from the road surface. The rate at which the suspension dissipates the energy and the amount of energy that is absorbed is how the suspension defines the vehicles ride characteristics. Ride characteristics are designed into the suspension system and are not adjustable. The ride characteristics are mentioned in this description in order to aid in the understanding of the functions of the suspension system. The suspension system must allow for the vertical movement of the tire and wheel assembly as the vehicle travels over irregular road surfaces while maintaining the tire's horizontal relationship to the road.

This requires that the steering knuckle be suspended between a lower control arm and a strut assembly. The lower control arm attaches from the steering knuckle at the outermost point of the control arm. The attachment is through a ball and socket type joint. The innermost end of the control arm attached at 2 points to the vehicle frame through semi-rigid bushings. The upper portion of the steering knuckle is attached to a strut assembly. The strut assembly then connects to the vehicle body by way of an upper bearing. The steering knuckle is allowed to travel up and down independent of the vehicle body structure and frame.

This up and down motion of the steering knuckle as the vehicle travels over bumps is absorbed predominantly by the coil spring. This spring is retained under tension over the strut assembly. A strut is used in conjunction with this system in order to dampen out the oscillations of the coil spring. A strut is a basic hydraulic cylinder. The strut is filled with oil and has a moveable shaft that connects to a piston inside the strut. Valves inside the shock absorber offer resistance to oil flow and consequently inhibit rapid movement of the piston and shaft. Each end of the shock absorber is connected in such a fashion to utilize this recoil action of a spring alone. Each end of the strut is designed as the connection point of the suspension system to the vehicle and acts as the coil spring seat. This allows the strut to utilize the dampening action to reduce the recoil of a spring alone. The lower control arm is allowed to pivot at the vehicle frame in a vertical fashion. The ball joint allows the steering knuckle to maintain the perpendicular relationship to the road surface.

Front suspensions systems utilize a stabilizer shaft. The stabilizer bar connects between the left and right lower control arm assemblies through the stabilizer link and stabilizer shaft insulators. This bar controls the amount of independent movement of the suspension when the vehicle turns. Limiting the independent movement defines the vehicles handling characteristics on turns.

Special Tools

Illustration Tool Number/Description CH-43631 CH-49455 J-43631 Ball Joint Separator CH-48845 Strut Spring Compressor CH-49375 Spanner (Wrench)

Scheme 12

Scheme 12: Special Tools
Scheme 12: Special Tools

Scheme 13

Scheme 13
Scheme 13

Scheme 14

Scheme 14
Scheme 14

More articles — Suspension