Service Procedure
The following procedure provides instructions for inspecting and replacing the nut that attaches the lower ball joint stud to the knuckle. In a few instances, the results of the inspection may determine that the lower control arm and knuckle need replacement.
Front Lower Ball Joint to Knuckle Retaining Nut Inspection
See the appropriate Service Manual sections for additional information, illustrations and required tool usage.
1. Turn the ignition switch to the OFF position so that front wheels can be steered.
2. Raise the vehicle on a suitable hoist and support as necessary.
3. On SRX models, remove both front wheel and tire assemblies.
4. Place a suitable support under the front lower control arm.
5. Check the torque of the lower ball joint stud to knuckle retaining nut.
A. Was the ball stud nut torque less than 30 Nm (22 lb ft)? If no, nut must be replaced. Remove the original nut and continue to Step B to determine the correct tightening specification of the new nut. If yes, the lower control arm (which includes the ball stud), knuckle, and retaining nut must be replaced. Contact a representative at the PQC to order parts. Refer to the Parts section in this bulletin for ordering information. Proceed to the Front Lower Control Arm and Knuckle Replacement Procedure when parts are received.
B. Did the ball stud assembly separate from the knuckle when the nut was removed? If yes, replace only the nut.
Tighten
Tighten the NEW nut to 30 Nm (22 lb ft), and then an additional 180 degrees.
C. If no, replace only the nut.
Tighten
^ CTS/SRX: Tighten the NEW nut to 100 Nm (74 lb ft).
^ XLR/Corvette: Tighten the NEW nut to 75 Nm (55 lb ft).
6. Remove the support from the lower control arm.
7. Repeat the inspection on the opposite side.
8. On SRX models, install the wheel and tire assemblies.
Tighten
Tighten the wheel nuts to 140 Nm (103 lb ft).
9. On SRX and CTS models, remove the supports and lower the vehicle.
10. On XLR and Corvette models, proceed to the Rear Lower Ball Joint to Knuckle Retaining Nut Procedure.
Rear Lower Ball Joint to Knuckle Retaining Nut Inspection - XLR and Corvette Only
See the appropriate Service Manual sections for additional information, illustrations, and required tool usage.
1. The vehicle should still be on a hoist with the supports in place as necessary.
2. Remove both rear wheel and tire assemblies.
3. Disconnect the linkage attaching the height sensor to the control arm.
4. Remove the bolts attaching the brake caliper bracket to the knuckle and remove the caliper/bracket assembly. Support the caliper/bracket assembly as necessary.
5. Mark the position of the brake rotor on the bearing hub assembly.
6. Remove the brake rotor.
7. Remove the outer tie rod and separate the tie rod stud from the knuckle.
8. Disconnect the wheel speed sensor electrical connector from the bearing hub.
9. Remove the two bolts attaching the park brake cable to the knuckle and unhook the cable from the adjuster.
10. On Corvette models, remove the nuts and stabilizer bar from the lower control arm.
11. Support the lower control arm as necessary.
12. Remove the lower shock mounting bolt from the lower control arm.
13. Remove the large nut attaching the drive axle to the bearing hub.
14. On Corvette models, remove the snap ring from the leaf spring height adjuster.
15. On Corvette models, count and record the number of exposed threads between the top of the nut and the snap ring groove on the height adjuster.
16. On Corvette models, remove the nut from the height adjuster.
17. Carefully lower the lower control arm until it is unloaded from the leaf spring.
18. Remove the upper control arm ball joint stud to knuckle retaining nut.
19. Separate the upper control arm ball joint stud from the knuckle.
20. Remove the drive axle from the bearing hub.
21. Check the torque of the lower ball joint stud to knuckle retaining nut.
A. Was the ball stud nut torque less than 30 Nm (22 lb ft)? If no, the nut must be replaced. Remove the original nut and continue to Step B to determine the correct tightening specification of the new nut. If yes, the lower control arm (which includes the ball stud), knuckle, and retaining nut must be replaced. Proceed to Rear Lower Control Arm and Knuckle Replacement Procedure.
B. Did the ball stud assembly separate from the knuckle when the nut was removed? If yes, replace only the nut.
Tighten
Tighten the NEW nut to 30 Nm (22 lb ft), and then an additional 180 degrees.
C. If no, replace only the nut.
Tighten
Tighten the NEW nut to 75 Nm (55 lb ft).
22. Install the drive axle into the bearing hub.
23. Install the upper ball joint stud to the knuckle, and install the retaining nut.
Tighten
Tighten the nut to 30 Nm (22 lb ft), and then an additional 180 degrees.
24. Carefully raise the lower control arm.
25. On Corvette models, install the height adjuster bolt and nut.
Tighten
Tighten the nut until the correct amount of threads (recorded earlier) are visible. Install the snap ring.
26. Install the large nut on the drive axle.
Tighten
Tighten the nut to 160 Nm (118 lb ft)
27. Position the lower shock mount to the lower control arm and install the fasteners.
Tighten
Tighten the bolt (not the nut) to 220 Nm (162 lb ft).
28. On Corvette models, position the stabilizer bar to the lower control arm and install the nut.
Tighten
Tighten the nut to 72 Nm (53 lb ft).
29. Position the park brake cable and bracket to the knuckle and install the bolts.
Tighten
Tighten the bolts to 30 Nm (22 lb ft).
30. Connect the outer tie rod to the knuckle and install the nut.
Tighten
Tighten the nut to 20 Nm (15 lb ft), and then an additional 160 degrees.
31. Connect the wheel speed sensor electrical connector to the bearing hub.
32. Using the mark made earlier, align and install the brake rotor to the bearing hub.
33. Position the brake caliper and bracket to the knuckle and install the attaching bolts.
Tighten
Tighten the bolts to 175 Nm (129 lb ft).
34. Connect the height sensor linkage to the control arm.
35. Repeat the inspection procedure on the opposite side of the vehicle.
36. Install the rear wheel and tire assemblies.
Tighten
Tighten the wheel nuts to 140 Nm (103 lb ft).
37. Remove any supports and lower the vehicle.
Front Lower Control Arm and Knuckle Replacement - SRX Models
This procedure should only be performed if the results in the INSPECTION procedure indicate that replacement of these parts are required.
See the appropriate Service Manual sections for additional information, illustrations, and required tool usage.
1. Raise the vehicle on a suitable hoist and support.
2. Remove the front wheel and tire assembly.
3. Remove the bolts attaching the brake caliper bracket to the knuckle and remove the caliper/bracket assembly. Support the caliper/bracket assembly as necessary.
4. Mark the position of the brake rotor on the bearing hub assembly.
5. Remove the bolt attaching the rotor the bearing hub and remove the rotor.
6. Remove the outer tie rod end nut.
7. Remove the outer tie rod end from the knuckle.
8. Disconnect the ABS wheel speed sensor electrical connector from the bearing hub.
9. Remove the nut attaching the stabilizer bar link to the lower control arm and separate the link from the arm.
10. Remove the two bolts and remove the bracket that attaches the brake hose and harness to the knuckle.
11. Place the support under the lower control arm.
12. Remove the nut attaching the upper ball joint stud to the knuckle.
13. Remove the nut attaching the lower ball joint stud to the knuckle.
14. Remove the nut attaching the strut yoke to the lower control arm.
15. On AWD models, remove the large nut attaching the drive axle to the bearing hub.
16. Separate the knuckle from the upper and lower ball studs.
17. On AWD models, remove the knuckle from the drive axle.
18. Disconnect the ABS wiring harness from the lower control arm.
19. Remove the nut attaching the lower control arm to the frame.
20. Remove the bolt attaching the left side of the steering gear to the frame.
21. Loosen, BUT DO NOT REMOVE, the bolt attaching the right side of the steering gear to the frame.
22. Raise the left side of the steering gear up from the frame to obtain the necessary clearance to remove the bolt attaching the rear of the lower control arm to the frame.
23. Remove both bolts attaching the lower control arm to the frame.
24. Remove the bolts attaching the bearing hub to the knuckle and remove the bearing hub.
25. Install the hearing hub on the NEW knuckle and install the bolts.
Tighten
Tighten the bolts to 135 Nm (99 lb ft).
26. Position the NEW lower control arm to the frame and install the bolts and nuts. DO NOT tighten the nuts at this time.
27. Reposition the steering gear into the frame mount and install the left bolt.
Tighten
Tighten both bolts to 120 Nm (88 lb ft).
28. Connect the ABS harness to the lower control arm.
29. Install the ball joint stud on the NEW lower control arm to the NEW knuckle and install the nut.
Tighten
Tighten the nut to 20 Nm (15 lb ft), and then an additional 210 degrees.
30. On AWD models, install the drive axle into the bearing hub.
31. Install the ball joint stud on the upper control arm to the NEW knuckle and install the nut.
Tighten
Tighten the nut to 20 Nm (15 lb ft), and then an additional 210 degrees.
32. Install the large nut on the drive axle.
Tighten
Tighten the nut to 160 Nm (118 lb ft).
33. Attach the strut yoke to the lower control arm and install the nut.
Tighten
Tighten the nut to 180 Nm (133 lb ft).
34. Position the bracket for the brake hose to the knuckle and install the bolts.
Tighten
Tighten the NEW nut to 30 Nm (22 lb ft), and then an additional 180 degrees.
35. Connect the stabilizer link to the lower control arm and install the nut.
Tighten
Tighten the nut to 110 Nm (81 lb ft).
36. Connect the ABS electrical connector to the bearing hub.
37. Connect the outer tie rod end to the knuckle and install the nut.
Tighten
Tighten the nut to 70 Nm (52 lb ft).
38. Align the rotor to the mark made earlier and install on the hub.
39. Install the bolt attaching the rotor to the hub.
Tighten
Tighten the bolt to 14 Nm (124 lb in).
40. Position the brake caliper/bracket assembly on the knuckle and install the attaching bolts.
Tighten
Tighten the bolts to 130 Nm (96 lb ft).
41. Place supports under the lower control arm to raise the arm to normal curb height position.
Tighten
Tighten the lower control arm attaching bolt and nuts to 135 Nm (99 lb ft).
42. Install the front wheel/tire assembly.
Tighten
Tighten the wheel nuts to 140 Nm (103 lb ft).
43. Repeat the procedure on the opposite side of the vehicle if necessary.
44. Check the wheel alignment.
45. Lower the vehicle.
Front Lower Control Arm and Knuckle Replacement - CTS Models
This procedure should only be performed if the results in the INSPECTION procedure indicate that replacement of these parts are required.
See the appropriate Service Manual sections for additional information, illustrations, and required tool usage.
1. Raise the vehicle on a suitable hoist and support.
2. Remove the wheel and tire assembly.
3. Remove the bolts attaching the brake caliper bracket to the knuckle and remove the caliper/bracket assembly. Support the caliper/bracket assembly as necessary.
4. Mark the position of the brake rotor on the bearing hub assembly.
5. Remove the bolt attaching the rotor the bearing hub and remove the rotor.
6. Remove the outer tie rod end nut.
7. Separate the outer tie rod end from the knuckle.
8. Remove the three bolts attaching the bearing hub to the knuckle.
9. Remove the bearing hub from the knuckle and disconnect the electrical connector from the backing plate. Route the electrical connector and harness through the knuckle.
10. Remove the bolts attaching the shock absorber to the lower control arm.
11. Remove the stabilizer link nut and disconnect the link from the lower control arm.
12. Place a support under the lower control arm.
13. Remove the nut attaching the lower ball joint stud to the knuckle.
14. Separate the lower control arm ball stud from the knuckle and carefully lower the lower control arm.
15. Remove the nut attaching the upper ball joint stud to the knuckle.
16. Separate the upper ball joint stud from the knuckle and remove the knuckle from the vehicle.
17. Remove the three ABS harness clips from the lower control arm.
18. Remove the nuts and bolts that attach the lower control arm to the frame.
19. Install the NEW lower control arm to the frame and install the bolts and nuts. DO NOT tighten the nuts at this time.
20. Install the three ABS harness clips to the new lower control arms.
21. Install the ball joint stud on the NEW lower control arm to the NEW knuckle and install the nut.
Tighten
Tighten the nut to 20 Nm (15 lb ft), and then an additional 210 degrees.
22. Carefully raise the support under the lower control arm, install the ball joint stud on the upper control arm to the NEW knuckle, and install the nut.
Tighten
Tighten the nut to 20 Nm (15 lb ft), and then an additional 210 degrees.
23. Position the stabilizer link to the lower control arm and install the nut.
Tighten
Tighten the nut to 50 Nm (37 lb ft).
24. Position the shock absorber to the lower control arm and install the bolts.
Tighten
Tighten the bolts to 25 Nm (18 lb ft).
25. Route the electrical connector and harness through the knuckle and connect the connector to the backing plate.
26. Position the bearing hub to the knuckle and install the three bolts.
Tighten
Tighten the bolts to 135 Nm (99 lb ft).
27. Install the outer tie rod end to the knuckle and install the nut.
Tighten
Tighten the nut to 75 Nm (55 lb ft).
28. Using the mark made earlier, align the brake rotor to the bearing hub and install the retaining screw.
Tighten
Tighten the screw to 14 Nm (124 lb in).
29. Install the brake caliper and bracket assembly to the knuckle and install the two bolts.
Tighten
Tighten the bolts to 136 Nm (100 lb ft).
30. Place supports under the lower control arm to raise the arm to the normal curb height position.
Tighten
Tighten the lower control arm nuts to 135 Nm (99 lb ft).
31. Install the wheel and tire assembly.
Tighten
Tighten the wheel nuts to 140 Nm (103 lb ft).
32. Repeat the procedure on the opposite side of the vehicle if necessary.
33. Check the wheel alignment.
34. Lower the vehicle.
Front Lower Control Arm and Knuckle Replacement - XLR and Corvette Models
This procedure should only be performed if the results in the INSPECTION procedure indicate that replacement of these parts are required.
See the appropriate Service Manual sections for additional information, illustrations, and required tool usage.
1. Raise the vehicle on a suitable hoist and support.
2. Remove the wheel and tire assembly.
3. Remove the bolts attaching the brake caliper bracket to the knuckle and remove the caliper/bracket assembly. Support the caliper/bracket assembly as necessary.
4. Mark the position of the brake rotor on the bearing hub assembly.
5. Remove the brake rotor.
6. Remove the outer tie rod end nut and separate the stud from the knuckle.
7. Disconnect the wheel speed sensor electrical connector.
8. Remove the stabilizer link nut and disconnect the link from the lower control arm.
9. Disconnect the linkage for the ride height sensor.
10. Remove the bolts attaching the shock absorber to the lower control arm.
11. Place supports under the lower control arm.
12. Remove the nut attaching the upper control arm ball joint stud to the knuckle.
13. Separate the upper control arm ball stud from the knuckle.
14. Remove the nut attaching the lower control arm ball joint stud to the knuckle.
15. Separate the lower control arm ball stud from the vehicle and carefully lower the lower control arm.
16. Remove the knuckle from the vehicle.
17. Remove the bolts attaching the bearing hub to the knuckle.
18. Transfer the bearing hub to NEW knuckle and install the bolts.
Tighten
Tighten the bolts to 130 Nm (96 lb ft).
19. Remove the screw for the ABS harness mounting bracket and transfer the bracket and screw to the NEW knuckle.
Tighten
Tighten the screw to 3 Nm (27 lb in).
20. Remove the screw for the ABS harness bracket on the lower control arm.
21. Remove the nuts and bolts that attach the lower control arm to the frame and remove the lower control arm.
22. Install the NEW lower control arm to the frame and install the bolts and nuts. DO NOT tighten at this time.
23. Install the ABS harness bracket to the NEW lower control arm and install the screw.
Tighten
Tighten the screw to 3 Nm (27 lb in).
24. Install the ball joint stud on the NEW lower control arm to the NEW knuckle and install the nut.
Tighten
Tighten the bolts to 20 Nm (15 lb ft), and then an additional 210 degrees.
25. Carefully raise the support under the lower control arm, install the ball joint stud on the upper control arm to the NEW knuckle, and install the nut.
Tighten
Tighten the nut to 20 Nm (15 lb ft), then an additional 210 degrees.
26. Position the shock absorber to the lower control arm and install the attaching bolts.
Tighten
Tighten the bolts to 28 Nm (21 lb ft).
27. Connect the ride height sensor linkage.
28. Position the stabilizer bar to the lower control arm and install the nut.
Tighten
Tighten the nut to 72 Nm (53 lb ft).
29. Connect the wheel speed sensor electrical connector.
30. Connect the outer tie rod end to the knuckle and install the nut.
Tighten
Tighten the nut to 20 Nm (15 lb ft), then an additional 160 degrees.
31. Using the mark made earlier, align and install the brake rotor.
32. Install the brake caliper and bracket assembly to the knuckle and install the two bolts.
Tighten
Tighten the bolts to 175 Nm (129 lb ft).
33. Place the supports under the lower control arm to raise the arm to the normal curb height position.
Tighten
Tighten the lower control arm nuts to 175 Nm (129 lb ft).
34. Install the front wheel and tire assembly.
Tighten
Tighten the wheel nuts to 140 Nm (103 lb ft).
35. Repeat the procedure on the opposite side of the vehicle if necessary.
36. Check the wheel alignment.
37. Lower the vehicle.
Rear Lower Control Arm and Knuckle Replacement - XLR and Corvette
2004 Cadillac XLR & Chevrolet Corvette
This procedure should only be performed if the results in the INSPECTION procedure indicate that replacement of these parts are required.
See the appropriate Service Manual sections for additional information, illustrations, and required tool usage.
Important:
This procedure is based on the vehicle being partially disassembled in the INSPECTION procedure.
1. Remove the lower ball joint stud to knuckle retaining nut.
2. Separate the knuckle from the lower control arm.
3. Remove the bolts attaching the bearing hub and park brake assembly to the knuckle.
4. Install the bearing hub and park brake assembly and the bolts on the new knuckle.
Tighten
Tighten the bolts to 130 Nm (96 lb ft).
5. Remove the nuts from the bolts that attach the lower control arm to the frame.
Important:
On Corvette models, the clearance for removal of the left side front bolt is limited, however it can be removed.
6. Position the new control arm to the frame and install the bolts and nuts. DO NOT tighten at this time.
7. Install the lower ball joint stud in the knuckle and install a NEW nut.
Tighten
Tighten the nut to 20 Nm (15 lb ft), and then an additional 210 degrees.
8. Install the drive axle into the bearing hub.
9. Install the upper ball joint stud to the knuckle and install the retaining nut.
Tighten
Tighten the nut to 30 Nm (22 lb ft), and then an additional 180 degrees.
10. Carefully raise the lower control arm.
11. On Corvette models, install the height adjuster bolt and nut
Tighten
Tighten the nut until the correct amount of threads (recorded earlier) are visible. Install the snap ring.
12. Install the large nut on the drive axle.
Tighten
Tighten the nut to 160 Nm (118 lb ft).
13. Position the lower shock mount to the lower control arm and install the fasteners.
Tighten
Tighten the bolt (not the nut) to 220 Nm (162 lb ft).
14. On Corvette models, position the stabilizer bar to the lower control arm and install the nut.
Tighten
Tighten to 72 Nm (53 lb ft).
15. Attach the park brake cable to the adjuster, position the park brake cable bracket to the knuckle, and install the two bolts.
Tighten
Tighten to 30 Nm (22 lb ft).
16. Connect the outer tie rod to the knuckle and install the nut.
Tighten
Tighten to 20 Nm (15 lb ft), and then an additional 160 degrees.
17. Connect the wheel speed sensor electrical connector to the bearing hub.
18. Using the mark made earlier, align and install the brake rotor.
19. Position the brake caliper and bracket to the knuckle and install the bolts.
Tighten
Tighten to 175 Nm (129 lb ft).
20. Connect the height sensor linkage to the control arm.
21. Place supports under the lower control arm to raise the arm to the normal curb height position.
Tighten
^ Tighten the FRONT lower control arm nuts to 145 Nm (107 lb ft).
^ Tighten the REAR lower control arm nuts to 95 Nm (70 lb ft).
23. Remove the supports from the lower control arm.
24. Repeat the procedure on the opposite side of the vehicle if necessary.
25. Install the rear wheel and tire assemblies.
Tighten
Tighten the wheel nuts to 140 Nm (103 lb ft).
26. Check the wheel alignment.
27. Lower the vehicle.