This procedure covers the removal and replacement of the lower control arm on a 2023 Chevrolet Bolt EUV, including disconnection of the ball joint and control arm mounting bolts.

Warnings

Tools required

Parts

• Lower control arm assembly × 1 — Use OEM specification
• Ball joint cotter pin × 1 — Use OEM specification

Preparation

1. Ensure vehicle is on level ground and parking brake is engaged
2. Verify vehicle is powered off completely
3. Loosen wheel lug nuts while vehicle is on ground (do not remove)
4. Raise vehicle with floor jack at manufacturer-recommended jacking point
5. Support vehicle securely on jack stands at designated lift points
6. Remove wheel completely
7. Spray penetrating oil on ball joint nut, control arm bolts, and cotter pin if components show corrosion

Procedure

1. 1

   Access the lower control arm
   With the wheel removed, visually locate the lower control arm. It connects from the subframe to the steering knuckle via the ball joint. Clean the area around fasteners with a wire brush if necessary to expose hardware clearly.
2. 2

   Remove ball joint cotter pin
   Locate the cotter pin securing the ball joint castle nut at the steering knuckle. Use cotter pin pliers to straighten the pin ends, then pull the cotter pin out completely and discard. Do not reuse the old cotter pin.
   ℹ️If cotter pin is severely corroded, you may need to drive it through with a punch.
3. 3

   Remove ball joint nut
   Using an 18mm socket, remove the ball joint castle nut from the ball joint stud. Leave the nut threaded on a few turns initially to prevent the knuckle from falling when the taper breaks. Use a ball joint separator or pickle fork to break the taper between the ball joint stud and the steering knuckle. Once taper is broken, remove the nut completely.
   ⚠Do not strike the ball joint stud directly with a hammer as this can damage the threads.
4. 4

   Separate ball joint from knuckle
   With the taper broken and nut removed, pull the steering knuckle assembly outward to separate the ball joint stud from the knuckle. You may need to use a pry bar for leverage. Support the knuckle assembly with wire or bungee cord to prevent strain on the CV axle and brake hose.
   ⚠Do not allow the knuckle to hang freely. This can damage the CV joint and brake lines.
5. 5

   Remove rear control arm bolt
   Locate the rear control arm mounting bolt that secures the control arm to the subframe (rearward position). Using a 21mm socket and wrench, remove this bolt completely. Note the orientation of any washers or spacers for reinstallation. The control arm will now pivot on the front bolt only.
6. 6

   Remove front control arm bolt
   Remove the front control arm mounting bolt at the subframe using a 21mm socket. The control arm is now free and can be removed from the vehicle. Inspect the bolt holes in the subframe for damage or excessive wear.
7. 7

   Install new control arm
   Position the new lower control arm into place. Insert the front control arm bolt first, threading it through the subframe and control arm bushing. Do not tighten. Insert the rear control arm bolt and thread it by hand. Both bolts should be snug but NOT torqued at this time.
   ⚠Control arm bushings must be torqued with vehicle at ride height (weight on wheels) to prevent bushing bind and premature failure.
8. 8

   Connect ball joint to knuckle
   Guide the ball joint stud into the hole in the steering knuckle. You may need to use a pry bar to align the knuckle. Thread the new ball joint castle nut onto the stud by hand, ensuring it threads smoothly. Torque the ball joint nut to specification.
   Torque spec

   Ball Joint Nut88 Nm (65 lb-ft)
9. 9

   Install new cotter pin
   Align the castle nut slots with the hole in the ball joint stud. If slots do not align, tighten the nut slightly (never loosen) until alignment is achieved. Insert a new cotter pin through the stud hole and bend the ends around the nut to secure. Ensure the pin cannot back out.
   ℹ️Never loosen a properly torqued castle nut to align cotter pin holes. Only tighten further if needed.
10. 10

    Reinstall wheel
    Mount the wheel onto the hub and thread all lug nuts by hand to prevent cross-threading. Tighten lug nuts in a star pattern snug but do not torque yet. The wheel must be installed to load the suspension before torquing control arm bolts.
    Torque spec

    Wheel Lug Nuts136 Nm (100 lb-ft)
11. 11

    Lower vehicle to load suspension
    Carefully lower the vehicle from the jack stands using the floor jack until the full weight of the vehicle is resting on the wheels, but keep the jack slightly engaged for safety. The suspension must be at normal ride height for the next step.
    ⚠Ensure the vehicle is stable and on level ground before working underneath.
12. 12

    Torque control arm bolts at ride height
    With the vehicle weight on the wheels, crawl under the vehicle and torque both the front and rear control arm bolts to specification. This ensures the control arm bushings are set in their neutral position and will not bind during suspension travel.
    Torque spec

    Control Arm Bolts165 Nm (122 lb-ft)
13. 13

    Final torque wheel lug nuts
    Raise the vehicle slightly to remove weight from the wheel. Torque all lug nuts to specification in a star pattern to ensure even seating. Lower the vehicle completely and remove the jack.
    Torque spec

    Wheel Lug Nuts136 Nm (100 lb-ft)

Reassembly

1. Ensure all fasteners are torqued to specification
2. Verify new cotter pin is properly installed and secured
3. Check that CV axle boot and brake lines were not damaged during the procedure
4. Verify there is adequate clearance between all suspension components and no interference

Verification

• Start the vehicle and turn the steering wheel lock-to-lock while stationary to check for binding or interference
• Test drive the vehicle at low speed and verify no unusual noises from the suspension
• Check for proper steering response and straight-line tracking
• Schedule a professional wheel alignment as suspension geometry has been altered

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