This procedure covers removal and replacement of the upper control arm on the rear suspension of a 2016-2024 Hyundai Tucson with 2.5L AWD engine.

Warnings

Tools required

Parts

• Upper control arm assembly × 1 — Use OEM specification
• Upper ball joint castle nut × 1 — Use OEM specification
• Control arm mounting bolts × 2 — Use OEM specification if corroded

Preparation

1. Park vehicle on level surface and set parking brake
2. Loosen wheel lug nuts while vehicle is on ground
3. Raise rear of vehicle and support on jack stands under frame rails
4. Remove rear wheel on side being serviced
5. Spray penetrating oil on control arm bolts and ball joint nut, allow to soak 10-15 minutes
6. Position floor jack under rear knuckle to support suspension at ride height

Procedure

1. 1

   Support the knuckle assembly
   Position floor jack under the rear knuckle assembly to support the weight of the suspension components. Raise jack until suspension is at approximately normal ride height. This prevents the suspension from dropping when the upper control arm is disconnected.
2. 2

   Remove ball joint castle nut
   Remove the cotter pin from the upper ball joint castle nut if equipped. Using a 17mm or 19mm socket, remove the castle nut from the upper ball joint stud. Do not reuse this nut.
3. 3

   Separate ball joint from knuckle
   Install ball joint separator tool between the upper control arm and the knuckle. Tighten the tool to apply pressure, then strike the knuckle boss area with a dead blow hammer to shock the taper loose. Alternatively, use a pickle fork to wedge between the control arm and knuckle. Remove the tool once the ball joint stud releases from the knuckle.
   ⚠Ball joint will separate suddenly under pressure - keep hands clear of pinch points
4. 4

   Remove front control arm bolt
   Locate the front mounting bolt securing the upper control arm to the subframe. This is typically a 17mm or 19mm head bolt. Use a breaker bar to loosen, then remove the bolt completely. Note the orientation of any washers or spacers.
5. 5

   Remove rear control arm bolt
   Locate the rear mounting bolt securing the upper control arm to the subframe. Use a breaker bar to loosen, then remove the bolt completely. The control arm should now be free to remove. Note the orientation of any washers or spacers for reassembly.
6. 6

   Remove upper control arm
   Carefully maneuver the upper control arm out of the suspension area. You may need to adjust the jack height slightly to provide clearance. Inspect the ball joint boot and pivot bushings on the old arm to identify wear patterns.
7. 7

   Clean mounting surfaces
   Use a wire brush to clean the control arm mounting bolt holes in the subframe and the ball joint taper in the knuckle. Remove any rust, debris, or old thread locker compound. This ensures proper seating and torque values.
8. 8

   Install new upper control arm
   Position the new upper control arm into place. Insert the ball joint stud into the knuckle taper first, ensuring it seats fully. You may need to adjust jack height to align the mounting bolt holes with the subframe.
9. 9

   Install control arm mounting bolts finger tight
   Insert both front and rear control arm mounting bolts with any washers or spacers in the correct orientation. Thread the bolts in by hand and tighten just until snug. DO NOT torque these bolts yet - they must be torqued with vehicle weight on the wheels.
   ⚠Do not torque control arm bolts at this time - must be done with vehicle at ride height
10. 10

    Install and torque ball joint nut
    Install the new castle nut onto the upper ball joint stud. Torque the nut to specification. If the castle nut slots do not align with the cotter pin hole, tighten further (never loosen) until the next slot aligns. Install new cotter pin and bend ends to secure.
    Torque spec

    Ball Joint Nut88 Nm (65 lb-ft)
11. 11

    Reinstall wheel and lower vehicle
    Remove the floor jack from under the knuckle. Reinstall the rear wheel and thread lug nuts on by hand. Lower the vehicle until the tires just touch the ground but the jack stands still support the vehicle weight.
12. 12

    Torque control arm bolts at ride height
    With the vehicle weight now on the wheels but still supported by jack stands, torque both the front and rear upper control arm mounting bolts to specification. This ensures the bushings are not preloaded in the wrong position.
    Torque spec

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

    Final wheel installation
    Raise the vehicle slightly and remove the jack stands. Lower the vehicle completely to the ground. Torque the wheel lug nuts to specification in a star pattern.
    Torque spec

    Wheel Lug Nuts136 Nm (100 lb-ft)

Reassembly

1. Ensure all fasteners are torqued to specification
2. Verify ball joint castle nut cotter pin is properly installed and secured
3. Confirm no tools or parts are left in the wheel well area

Verification

• Perform a visual inspection of all connections to ensure proper installation
• Bounce the rear of the vehicle and listen for any unusual noises from the suspension
• Test drive at low speed and verify normal handling without clunking or abnormal noises
• Have a professional alignment performed immediately, as upper control arm replacement affects camber and toe settings

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