Ball Joint - Upper

This procedure covers the removal and replacement of the upper ball joint on a 2023 Chevrolet Bolt EUV, requiring suspension disassembly and proper torque specifications for safety-critical fasteners.

Warnings

Tools required

Parts

• Upper ball joint assembly × 1 — Use OEM specification
• Ball joint castle nut × 1 — May come with ball joint
• Cotter pin × 1 — Use OEM specification

Preparation

1. Ensure vehicle is on level ground and parking brake is engaged
2. Chock rear wheels securely
3. Loosen wheel lug nuts while vehicle is still on ground
4. Lift front of vehicle and support on jack stands at manufacturer-specified jacking points
5. Remove wheel completely from side being serviced

Procedure

1. 1

   Locate and inspect upper ball joint
   Identify the upper ball joint where it connects the upper control arm to the steering knuckle. Inspect the boot for damage and verify this is the component requiring replacement. The upper ball joint is secured by a castle nut with cotter pin at the knuckle connection point.
2. 2

   Remove cotter pin from ball joint nut
   Straighten and remove the cotter pin from the castle nut securing the upper ball joint to the steering knuckle. Use needle nose pliers or a cotter pin removal tool. Discard the old cotter pin as a new one must be installed during reassembly.
3. 3

   Loosen ball joint castle nut
   Using the appropriate socket, loosen the castle nut on the upper ball joint stud but do not remove it completely yet. Leave the nut threaded on a few turns to protect the threads and prevent the knuckle from dropping suddenly when the taper breaks free.
4. 4

   Separate ball joint from knuckle
   Using a ball joint separator or pickle fork, break the taper between the ball joint stud and the steering knuckle. Position the tool properly and strike with a hammer or use a screw-type separator. Once the taper breaks free, support the knuckle and remove the castle nut completely.
   ⚠Tool may slip suddenly when taper releases. Keep face and hands clear of impact zone.
5. 5

   Remove upper control arm mounting bolts
   Locate the bolts securing the upper control arm (which contains the ball joint) to the vehicle frame or mounting bracket. Support the control arm with your hand or a jack. Remove the control arm mounting bolts completely. The upper ball joint may be integral to the control arm or replaceable separately depending on design.
   Torque spec

   Control Arm Bolts165 Nm (122 lb-ft)
6. 6

   Remove upper control arm assembly
   Lower the upper control arm assembly away from the mounting location. If the ball joint is integral to the control arm, the entire assembly will be replaced. If the ball joint is serviceable separately, it can now be pressed or bolted out of the control arm per manufacturer design.
7. 7

   Install new ball joint
   If ball joint is separate from control arm, press or bolt the new ball joint into the control arm following manufacturer specifications. If integral, proceed with the new control arm assembly. Ensure the ball joint boot is not damaged and is properly seated. Clean all mounting surfaces with a wire brush.
8. 8

   Install upper control arm to frame
   Position the upper control arm with new ball joint into the frame mounting location. Install the control arm mounting bolts finger-tight only at this stage. Do not torque these bolts yet as they must be torqued with vehicle weight on the suspension.
   ℹ️Control arm bolts must be torqued with vehicle at ride height per specifications.
   Torque spec

   Control Arm Bolts165 Nm (122 lb-ft)
9. 9

   Connect ball joint to steering knuckle
   Guide the upper ball joint stud through the hole in the steering knuckle. Ensure the stud seats fully into the taper. Install the new castle nut onto the ball joint stud and tighten to specification.
   Torque spec

   Ball Joint Nut88 Nm (65 lb-ft)
10. 10

    Install new cotter pin
    Align the castle nut slots with the cotter pin 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 hole and bend the ends to secure it properly.
    ⚠Never loosen castle nut to align cotter pin hole. Only tighten further if needed for alignment.
11. 11

    Reinstall wheel
    Mount the wheel back onto the hub and install lug nuts. Thread all lug nuts by hand first, then snug them in a star pattern. Do not fully torque yet as the vehicle needs to be lowered first.
    Torque spec

    Wheel Lug Nuts136 Nm (100 lb-ft)
12. 12

    Lower vehicle and torque fasteners
    Carefully lower the vehicle so the suspension is at normal ride height but keep the jack supporting some weight. Torque the upper control arm mounting bolts to specification with vehicle weight on the suspension. Fully lower the vehicle and torque the wheel lug nuts in a star pattern to specification.
    Torque spec

    Control Arm Bolts165 Nm (122 lb-ft)

    Wheel Lug Nuts136 Nm (100 lb-ft)

Reassembly

1. Verify all fasteners are torqued to specification
2. Ensure new cotter pin is properly installed and bent
3. Check that ball joint boot is not torn or displaced
4. Control arm bolts must be torqued at ride height, not with suspension hanging

Verification

• Bounce the front end of the vehicle and listen for any clunking or loose components
• Turn the steering wheel lock-to-lock while stationary to check for binding or noise
• Perform a visual inspection of the ball joint boot and verify no tears or displacement
• Test drive at low speed and verify normal steering response and no unusual noises
• Have front end alignment checked by a professional as soon as possible, as upper ball joint replacement affects alignment settings

More procedures for this vehicle