🔧 Prius - Front Lower Control Arm Replacement

You’ll be removing the front lower control arm(s) and installing new ones, then tightening everything at the correct ride height. Worn control arms (or their bushings/ball joint) can cause clunks, wandering, uneven tire wear, and poor braking stability.

Difficulty Level: Advanced | Estimated Time: 2.5-5.0 hours

Assumption: you’re replacing the front lower control arm(s), left and/or right.

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⚠️ Safety & Precautions

• ⚠️ Support your Prius with jack stands on solid ground; never rely on a floor jack alone.
• ⚠️ Keep hands clear when separating the ball joint; parts can release suddenly.
• ⚠️ Do not work under the car with the ignition ON; keep the key/fob away to prevent the car “waking up.”
• ⚠️ If using power tools, start all bolts by hand first to avoid cross-threading.
• ⚠️ No hybrid high-voltage disconnection is required for this job, but avoid orange cables and HV components.

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🔧 Required Tools

You'll need the following tools for this repair:

• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Safety glasses
• Mechanic gloves
• Breaker bar (1/2-inch drive)
• Torque wrench (20–200 Nm range)
• Socket set (8mm–22mm, 1/2-inch drive)
• Wrench set (12mm–22mm)
• Needle-nose pliers
• Hammer (16–24 oz)
• Pry bar (18–24 inch)
• Ball joint separator (specialty)
• Penetrating oil
• Paint marker

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Front lower control arm (left) - Qty: 1
• Front lower control arm (right) - Qty: 1
• Front lower ball joint cotter pin - Qty: 2
• Front lower control arm mounting hardware kit - Qty: 1

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📋 Before You Begin

• Park on level ground, shift to P, and set the parking brake.
• Place wheel chocks behind the rear wheels.
• Loosen the front wheel lug nuts about 1/2 turn using a 21mm socket and breaker bar (do not remove yet).
• Spray penetrating oil on the control arm bolts/nuts and sway bar end link nut(s); let it soak.
• Use a paint marker to mark bolt/nut positions where helpful (good habit for first-timers).

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Lift and secure the front of the car

• Use a floor jack on the front center jack point to lift the front.
• Set the car onto jack stands at the front support points.
• Give the car a gentle shake to confirm it’s stable before going underneath.

Step 2: Remove the front wheel

• Remove the lug nuts with a 21mm socket, then remove the wheel.
• Set the wheel under the rocker area as an extra safety backup.

Step 3: Disconnect the sway bar end link from the control arm

• Remove the end link nut using the correct socket and a matching wrench to hold the stud if it spins.
• If it spins, tighten slightly then loosen.

Step 4: Separate the ball joint from the steering knuckle

• Remove the cotter pin using needle-nose pliers.
• Loosen and remove the ball joint nut using the correct socket and breaker bar.
• Install a ball joint separator (specialty) and separate the ball joint from the knuckle.
  • A ball joint separator is a tool that pushes the stud out without hammering the threads.
• Support the knuckle so the brake hose isn’t stretched (use your hand or a gentle prop).

Step 5: Remove the control arm mounting bolts

• Locate the control arm’s body-side mounting bolts (front and rear mounts).
• Remove the bolts using a socket and breaker bar.
• If the arm is stuck, use a pry bar to coax it out of the mounts.

Step 6: Remove the control arm

• Pull the control arm out from the subframe area.
• Compare the old and new arms side-by-side (bushing positions and shape should match).

Step 7: Install the new control arm loosely

• Position the new control arm in place.
• Start the body-side mounting bolts by hand using a socket (do not fully tighten yet).
• Insert the ball joint stud into the knuckle and start the nut by hand.

Step 8: Reconnect the sway bar end link

• Install the end link to the control arm and tighten the nut using the proper socket and wrench.

Step 9: Torque fasteners (final tightening at ride height)

• Reinstall the wheel using a 21mm socket and snug the lug nuts.
• Lower the Prius so the suspension is at normal ride height (wheels on the ground) using the floor jack.
• Torque the control arm body-side bolts with a torque wrench: Torque to 166 Nm (122 ft-lbs) (each).
• Torque the ball joint nut with a torque wrench: Torque to 103 Nm (76 ft-lbs), then install a new cotter pin using needle-nose pliers.
• Torque the sway bar end link nut with a torque wrench: Torque to 55 Nm (41 ft-lbs).
• Torque the wheel lug nuts in a star pattern with a torque wrench: Torque to 103 Nm (76 ft-lbs).
• Ride-height tightening prevents bushing twist.

Step 10: Repeat on the other side (if replacing both)

• Use the same process for the opposite front corner.
• Replace control arms in pairs if bushings are worn on one side.

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✅ After Repair

• Test drive slowly at first and listen for clunks over bumps.
• Verify the steering wheel is centered and the car tracks straight.
• Get a 4-wheel alignment as soon as possible; control arm replacement changes alignment.
• Recheck lug nut torque after 25–50 miles using a torque wrench.

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💰 DIY vs Shop Cost

Shop Cost: $700-$1,400 (parts + labor)

DIY Cost: $160-$500 (parts only)

You Save: $540-$900 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2.5-5.0 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.