suspension

Front Struts - Pair

for 2021 Honda Civic 1.5L I4 Turbo · FWD

Difficulty

Advanced

Time

2.5 h

Tools

Steps

This procedure covers the complete replacement of both front strut assemblies on a 2016-2021 Honda Civic with the 1.5L turbocharged engine, including removal of related suspension components and proper torque specifications.

Warnings

⚠️CRITICAL SAFETY SYSTEM: Improperly installed struts can cause loss of vehicle control, wheel separation, and fatal accidents. If you are uncertain about any step, have this service performed by a qualified technician.

⚠️Coil springs store tremendous energy. If disassembling struts, use only proper coil spring compressors. Releasing a compressed spring can cause severe injury or death. Purchasing pre-assembled struts is strongly recommended.

⚠️Never work under a vehicle supported only by a jack. Always use jack stands rated for the vehicle weight on a solid, level surface.

⚠All torque specifications marked CRITICAL must be followed exactly. Under-torquing can allow components to separate; over-torquing can cause fastener failure.

⚠Suspension components are under load. Do not loosen fasteners unless vehicle is properly supported and suspension is unloaded.

ℹ️A front-end alignment is mandatory after strut replacement. Vehicle handling will be unsafe until properly aligned.

Tools required

Floor jack and jack stands rated for vehicle weightEssential

Torque wrench (20-180 Nm range)Essential

19mm socket for lug nutsEssential

14mm, 17mm, 19mm combination wrenchesEssential

14mm, 17mm, 19mm sockets and ratchetEssential

6mm Allen key (for sway bar link)Essential

Ball joint separator or pickle forkEssential

Pry bar

Breaker barEssential

Wire brush

Penetrating oil

Coil spring compressor (if using non-assembled struts)

Parts

Front strut assembly - left × 1 — Use OEM Honda or quality aftermarket (KYB, Monroe, Bilstein)
Front strut assembly - right × 1 — Use OEM Honda or quality aftermarket (KYB, Monroe, Bilstein)
Ball joint castle nut (if damaged) × 2 — 90304-SB3-003 or equivalent
Cotter pins for ball joints × 2 — New cotter pins required

Preparation

Park vehicle on level, solid surface and engage parking brake
Loosen front wheel lug nuts 1/4 turn while vehicle is on ground (do not remove)
Raise front of vehicle and support securely on jack stands at manufacturer-specified jacking points on the frame rails
Remove front wheels completely and set aside
Spray all suspension fasteners with penetrating oil and allow to soak for 10-15 minutes if vehicle has rust or corrosion
Verify new strut assemblies match old units in length, mounting configuration, and spring rate

Procedure

1
Remove sway bar link from strut
Locate the sway bar end link attached to the front strut. Insert a 6mm Allen key into the top of the link shaft to prevent rotation. Using a 14mm wrench on the nut, remove the upper sway bar link nut from the strut mounting point. The link will remain attached to the sway bar. Repeat for opposite side.
2
Disconnect brake line bracket from strut
Locate the brake line bracket bolted to the strut body. Remove the single mounting bolt (typically 10mm) securing the brake line bracket to the strut. Allow the brake line to hang freely without kinking or stretching. Do not disconnect any brake fittings.
⚠Do not allow brake line to hang unsupported or become kinked. Support with wire if necessary.
3
Remove ABS wheel speed sensor harness
Locate the ABS wheel speed sensor wire routed along the strut. Remove any clips or fasteners securing the sensor wire to the strut body. Carefully separate the wire from the strut to prevent damage during strut removal. The sensor remains installed in the knuckle.
4
Remove ball joint castle nut and separate
Locate the lower ball joint where the lower control arm connects to the steering knuckle. Remove the cotter pin and discard. Using a 19mm socket, remove the ball joint castle nut. Use a ball joint separator tool to press the ball joint stud out of the knuckle. Do not strike the ball joint with a hammer as this can damage the joint.
⚠The ball joint separator will apply significant force. Ensure tool is properly seated and hands are clear before applying pressure.
Torque spec
Ball Joint Nut84 Nm (62 lb-ft)
5
Remove strut-to-knuckle pinch bolt and nuts
Locate the two large bolts passing through the strut bracket into the steering knuckle (lower strut mounting). These are 17mm bolts. Remove both nuts from the back side of the knuckle, then drive the bolts out toward the front of the vehicle using a punch or drift. Note the orientation of the bolts for reinstallation.
⚠The knuckle will become loose and mobile once these bolts are removed. Support the knuckle and brake assembly to prevent damage to the CV axle or brake line.
Torque spec
Strut Bolts109 Nm (81 lb-ft)
6
Support strut from below
Position a floor jack or jack stand under the lower portion of the strut assembly to support its weight before removing the upper mounting nuts. Raise jack just enough to contact the strut and take the weight.
7
Remove strut tower mounting nuts
Open the vehicle hood. Locate the strut tower mounting nuts at the top of the strut assembly in the engine bay (three 14mm nuts forming a triangle pattern). While supporting the strut from below, remove all three upper strut tower nuts. The strut is now free from the vehicle.
⚠️Strut assembly weighs approximately 15-20 lbs and will drop when nuts are removed. Ensure strut is properly supported from below before removing the last nut.
Torque spec
Strut Tower Nuts50 Nm (37 lb-ft)
8
Remove strut assembly from vehicle
Carefully lower the jack supporting the strut. Maneuver the strut assembly out from the wheel well, routing it past the CV axle and brake components. You may need to pull the knuckle outward slightly to create clearance. Remove strut from vehicle and set aside.
9
Prepare new strut assembly
Unpack new strut assembly and verify all components are present. If using pre-assembled struts, remove any shipping spacers or protective covers from the shaft and mounting points. Transfer any components from old strut if required (bump stops, dust boots if not included with new assembly). Clean all mounting surfaces on the knuckle and strut tower with a wire brush.
10
Install new strut into vehicle
Maneuver the new strut assembly into the wheel well from below, routing past the CV axle and brake components. Align the upper mounting studs with the holes in the strut tower. You may need to use a pry bar to pull the knuckle outward for clearance. Support the strut with a jack from below.
11
Install strut tower nuts
From the engine bay, install all three upper strut tower nuts onto the mounting studs. Hand-tighten all three nuts, then torque to specification in a star pattern (tighten opposite nuts alternately to ensure even seating). The strut is now secured at the top.
Torque spec
Strut Tower Nuts50 Nm (37 lb-ft)
12
Connect strut to steering knuckle
Align the steering knuckle bracket with the strut mounting flange. Insert both strut-to-knuckle bolts from the front of the vehicle, passing through the strut bracket and knuckle. Install nuts on the back side and hand-tighten. Torque both nuts to specification. Ensure the knuckle is fully seated against the strut bracket.
Torque spec
Strut Bolts109 Nm (81 lb-ft)
13
Reconnect ball joint to knuckle
Align the lower control arm ball joint stud with the hole in the bottom of the steering knuckle. You may need to use a pry bar or jack to align the control arm height with the knuckle. Insert the ball joint stud into the knuckle and install the castle nut. Torque the nut to specification, then advance the nut if necessary to align the next castle slot with the cotter pin hole. Install a new cotter pin and bend the ends to secure.
⚠Never loosen the castle nut to align the cotter pin hole. Only tighten further to reach the next slot.
Torque spec
Ball Joint Nut84 Nm (62 lb-ft)
14
Reattach brake line bracket and ABS sensor wire
Reinstall the brake line bracket to the strut body using the mounting bolt. Secure the ABS wheel speed sensor wire to the strut using all original clips and fasteners. Ensure the wire has no kinks and will not contact rotating components or be pinched during suspension travel.
Torque spec
Mounting Bolts26 Nm (19 lb-ft)
15
Reconnect sway bar link
Align the sway bar end link with the mounting point on the strut. Install the upper link nut while holding the shaft with a 6mm Allen key to prevent rotation. Torque the nut to specification. Verify the link moves freely and is not binding.
Torque spec
Sway Bar Link58 Nm (43 lb-ft)
16
Repeat procedure for opposite side
Complete all steps (1-15) for the opposite front strut. Both struts should be replaced as a pair to maintain balanced handling characteristics.
17
Reinstall wheels and lower vehicle
Install both front wheels and hand-tighten all lug nuts in a star pattern. Lower vehicle until tires just contact the ground but vehicle weight is still on jack stands. Torque all lug nuts to specification in a star pattern. Fully lower vehicle and remove jack stands. Perform final lug nut torque check with vehicle on ground.
Torque spec
Wheel Lug Nuts129 Nm (95 lb-ft)

Reassembly

Verify all fasteners have been reinstalled and torqued to specification
Check that brake lines and ABS sensor wires are properly secured and routed away from rotating components
Verify cotter pins are installed in both ball joint castle nuts and properly bent
Test brake pedal feel before driving - pedal should be firm (no brake line damage occurred)

Verification

Bounce each front corner of the vehicle - struts should dampen movement within 1-2 bounces without excessive noise
Visually inspect all connections for proper seating and torque
Test drive vehicle in a safe area at low speed (under 25 mph) - verify no unusual noises, vibrations, or pulling to one side
MANDATORY: Schedule a professional front-end alignment within 50 miles of installation. Vehicle will experience uneven tire wear and poor handling until aligned
After 50-100 miles of driving, re-torque all suspension fasteners and lug nuts to specification