drivetrain

CV Axles - Front Pair

for 2021 Hyundai Tucson 2.5L I4 · AWD

Difficulty

Moderate

Time

1.8 h

Tools

Steps

Remove and replace both front CV axles on a 2016-2024 Hyundai Tucson 2.5L AWD, including disconnection from the front differential and wheel hubs.

Warnings

⚠️Vehicle must be securely supported on jack stands before working underneath. Never rely solely on a floor jack.

⚠Axle nuts are torqued to 250 Nm and must be loosened while vehicle is on the ground with wheels installed to prevent hub damage.

⚠Front differential fluid will drain when axles are removed. Have drain pan ready and plan to refill.

ℹ️New axle nuts are single-use and must be replaced. Do not reuse old axle nuts.

Tools required

Floor jack and jack standsEssential

Torque wrench (30-300 Nm range)Essential

Breaker barEssential

32mm axle nut socketEssential

17mm socket and ratchet

19mm socket and ratchetEssential

Ball joint separator or pickle forkEssential

Pry barEssential

Drain pan (2+ quart capacity)Essential

Hammer

Wire brush

CV axle puller (if stuck)

Parts

Front CV axle - driver side × 1 — Use OEM or equivalent for AWD 2.5L
Front CV axle - passenger side × 1 — Use OEM or equivalent for AWD 2.5L
Axle nut - driver side × 1 — New nut required, single-use
Axle nut - passenger side × 1 — New nut required, single-use
Cotter pin for ball joint nut × 2 — If equipped, verify before removal
Front differential gasket × 1 — Use if resealing differential cover

Fluids

75W-90 GL-5 Gear Oil — 1.5 qt

Preparation

Park vehicle on level surface and engage parking brake
Loosen both front axle nuts (32mm) with breaker bar while vehicle is still on ground with full weight on wheels - do NOT remove completely
Loosen front wheel lug nuts while vehicle is on ground
Raise front of vehicle and support securely on jack stands at manufacturer frame points
Remove both front wheels completely
Place drain pan under front differential to catch gear oil

Procedure

1
Remove driver side axle nut and wheel hub components
With vehicle raised and supported, completely remove the loosened 32mm axle nut from the driver side. Remove and discard the nut as it is single-use. If equipped with a cotter pin through the castle nut, remove and discard it first.
2
Disconnect driver side lower ball joint
Locate the lower ball joint nut connecting the control arm to the steering knuckle. Remove the cotter pin if present. Use a 19mm socket to remove the ball joint nut completely. Use a ball joint separator or pickle fork to separate the ball joint from the knuckle. Apply force at the joint, not the boot, to avoid damaging the ball joint boot.
⚠Do not damage the ball joint boot with the separator tool. Replace the boot if torn.
3
Remove driver side CV axle from hub
Pull the steering knuckle outward to disengage the CV axle splines from the wheel hub. If the axle is stuck in the hub, use a brass drift and hammer to tap the end of the axle shaft through the hub, or use a CV axle puller tool. Do not strike the threads directly.
4
Remove driver side CV axle from differential
Position drain pan directly under the differential where the CV axle enters. Use a pry bar between the inner CV joint housing and the differential case to pop the axle out of the differential. Pry evenly and firmly until the circlip releases. Gear oil will drain out immediately. Remove the axle completely from the vehicle.
⚠Approximately 1.5 quarts of gear oil will drain when axle is removed. Keep drain pan positioned correctly.
5
Remove passenger side axle nut and wheel hub components
Repeat the process for the passenger side. Completely remove the loosened 32mm axle nut. Remove and discard the cotter pin if equipped. Discard the axle nut as it must be replaced with a new one.
6
Disconnect passenger side lower ball joint
Remove the cotter pin from the passenger side ball joint nut if present. Use a 19mm socket to remove the ball joint nut. Separate the ball joint from the steering knuckle using a ball joint separator, taking care not to damage the boot.
7
Remove passenger side CV axle from hub and differential
Pull the steering knuckle outward to disengage the CV axle splines from the wheel hub. If stuck, tap carefully or use a puller. Position the drain pan under the passenger side differential entry point. Pry the inner CV joint out of the differential using a pry bar until the circlip releases. Remove the axle completely.
8
Clean and inspect hub and differential splines
Use a wire brush to clean the hub splines and differential opening on both sides. Inspect for any metal debris or damage. Remove any old circlips or debris from the differential. Check that new CV axles have new circlips properly installed on the inner joint.
9
Install new driver side CV axle into differential
Align the splines of the new driver side CV axle inner joint with the differential opening. Push firmly until the circlip seats with an audible click. Tug on the axle to verify it is locked in place and will not pull out.
10
Install driver side CV axle into wheel hub
Guide the outer CV axle shaft splines into the wheel hub. Push the knuckle inward while aligning the splines. The splines should slide in smoothly. Do not force - if resistance occurs, rotate the axle slightly to align splines properly.
11
Reconnect driver side ball joint and install new axle nut
Lift the lower control arm and insert the ball joint stud into the steering knuckle. Install the ball joint nut and torque to specification. Install a new cotter pin if equipped. Thread the new 32mm axle nut onto the CV axle shaft by hand as far as possible - do NOT torque yet.
Torque spec
Ball Joint Nut102 Nm (75 lb-ft)
12
Install new passenger side CV axle
Repeat the installation process for the passenger side. Insert the inner CV joint into the differential until it clicks into place and verify it is locked. Insert the outer shaft into the wheel hub, ensuring proper spline alignment. Reconnect the ball joint to the knuckle and torque the nut to specification. Install new cotter pin if equipped. Thread the new axle nut onto the shaft by hand.
Torque spec
Ball Joint Nut102 Nm (75 lb-ft)
13
Refill front differential with gear oil
Locate the front differential fill plug. Using a fluid pump or squeeze bottle, refill the front differential with 1.5 quarts of 75W-90 GL-5 gear oil through the fill hole. Fill until fluid reaches the bottom of the fill hole and begins to seep out. Reinstall and tighten the fill plug.
14
Reinstall wheels and lower vehicle
Install both front wheels and hand-tighten the lug nuts in a star pattern. Lower the vehicle until the wheels contact the ground but the suspension is not fully loaded. This prevents the hub from spinning when torquing the axle nut.
15
Torque axle nuts and wheel lug nuts to specification
With the vehicle lowered and brakes applied (or transmission in Park), torque both front axle nuts to 250 Nm (184 lb-ft) using a torque wrench. After torquing, stake the axle nut collar into the CV axle shaft groove using a punch and hammer, or install a new cotter pin if that style is used. Fully lower the vehicle to the ground. Torque all wheel lug nuts to 140 Nm (103 lb-ft) in a star pattern.
⚠Axle nut must be properly staked or pinned after torquing to prevent loosening during operation.
Torque spec
Axle Nut250 Nm (184 lb-ft)
Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

Ensure both axle nuts are properly torqued to 250 Nm and staked or pinned
Verify all ball joint nuts are torqued to 102 Nm with cotter pins installed if equipped
Confirm front differential is filled to proper level with 75W-90 GL-5 gear oil
Check that all lug nuts are torqued in star pattern to 140 Nm

Verification

Start the engine and verify no unusual noises from the CV axles or differential
Test drive the vehicle at low speed in a safe area, turning lock-to-lock in both directions to verify CV axles operate smoothly without clicking or binding
Check for gear oil leaks around both CV axle seals at the differential after test drive
Verify no vibration or unusual noise during acceleration and turning
Re-check axle nut torque after 50-100 miles of driving to ensure it has not loosened