Replace the rear axle seal on a 2016-2024 Hyundai Tucson 2.5L AWD to eliminate differential fluid leaks from the axle shaft interface.

Warnings

Tools required

Parts

• Rear axle shaft seal × 1 — Use OEM Hyundai/Kia part number
• Axle nut cotter pin or stake nut × 1 — Verify securing method for your model year
• Differential cover gasket or RTV sealant × 1 — Use Hyundai genuine gasket or OEM-spec RTV

Fluids

• 75W-90 GL-5 Gear Oil — 2 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Loosen rear wheel lug nuts while vehicle is on ground
3. Raise and support rear of vehicle on jack stands at manufacturer-approved lift points
4. Remove rear wheels completely
5. Mark driveshaft and differential yoke positions with paint for correct reassembly alignment
6. Place drain pan under rear differential

Procedure

1. 1

   Remove axle nut and wheel bearing assembly
   Have an assistant apply brakes or use a pry bar to prevent hub rotation. Remove and discard the cotter pin or unstake the axle nut. Use a breaker bar to loosen the axle nut (250 Nm). Remove the axle nut completely and retain for reinstallation.
   Torque spec

   Axle Nut250 Nm (184 lb-ft)
2. 2

   Disconnect CV joint from differential
   Locate the inner CV joint bolts connecting the axle shaft to the differential companion flange. Mark the position for correct reassembly. Remove all CV bolts and carefully support the axle shaft. You may need to rotate the hub to access all bolts.
   Torque spec

   CV Bolts61 Nm (45 lb-ft)
3. 3

   Remove axle shaft assembly
   Pull the outer end of the axle shaft through the hub bearing assembly. You may need to use a soft mallet to tap the shaft free. Once the inner CV joint is clear of the differential, carefully remove the entire axle shaft and set aside on a clean work surface.
   ⚠Support the axle shaft weight to avoid damaging CV boots or joints during removal.
4. 4

   Drain rear differential fluid
   If not already drained, remove the differential drain plug and allow all fluid to drain into the pan. If there is no drain plug, you will need to remove the differential cover. Clean the drain plug and inspect the magnetic tip for excessive metal debris which may indicate internal wear.
   ⚠Gear oil has a strong odor and can irritate skin. Avoid prolonged contact.
5. 5

   Remove differential cover (if necessary)
   If your differential does not have a drain plug or you need better access to the seal, remove all differential cover bolts in a crisscross pattern. Carefully break the gasket seal with a plastic scraper and remove the cover. Clean all gasket material from both the cover and differential housing mating surfaces.
   Torque spec

   Differential Cover Bolts35 Nm (26 lb-ft)
6. 6

   Remove old axle seal
   Inspect the seal bore area in the differential housing. Use an axle seal puller, slide hammer with seal adapter, or carefully use a pry bar to extract the old seal from its bore. Work carefully to avoid damaging the seal bore surface. Remove all remnants of the old seal.
   ⚠Do not gouge or scratch the seal bore surface as this will cause the new seal to leak.
7. 7

   Clean seal bore and inspect components
   Thoroughly clean the seal bore with a clean rag and solvent. Inspect the bore for any scratches, burrs, or damage. Inspect the axle shaft sealing surface for grooves, pitting, or wear. If the shaft surface is damaged, the shaft must be replaced or the new seal will leak. Wire brush any rust from the shaft sealing area.
8. 8

   Install new axle seal
   Lightly coat the outer diameter of the new seal with gear oil. Coat the seal lip with clean gear oil. Position the seal squarely in the bore with the lip facing inward toward the differential. Use a seal driver or appropriately sized socket to drive the seal evenly into the bore until it seats flush with the housing surface. Ensure the seal is not cocked or damaged during installation.
   ⚠The seal must be driven in straight and evenly. A cocked seal will leak immediately.
9. 9

   Reinstall differential cover (if removed)
   Install a new gasket or apply a continuous 3mm bead of Hyundai genuine RTV sealant to the cover mating surface. Install the cover and hand-tighten all bolts. Torque the differential cover bolts in a crisscross pattern to specification. If using RTV, allow 30 minutes cure time before filling with fluid.
   Torque spec

   Differential Cover Bolts35 Nm (26 lb-ft)
10. 10

    Reinstall axle shaft assembly
    Coat the axle shaft seal surface with clean gear oil. Carefully guide the inner CV joint into the differential housing, ensuring the shaft does not damage the new seal lip. Align the CV joint with the companion flange using your alignment marks. Insert the outer end of the shaft through the hub bearing.
11. 11

    Connect CV joint to differential
    Align the CV joint bolt holes with the companion flange using your reference marks. Install all CV bolts and torque to specification in a crisscross pattern. Ensure the joint is properly seated before final torquing.
    Torque spec

    CV Bolts61 Nm (45 lb-ft)
12. 12

    Install and torque axle nut
    Install the axle nut and tighten to specification using a calibrated torque wrench. Have an assistant apply brakes or use appropriate blocking to prevent rotation. After torquing, install a new cotter pin or stake the nut as applicable to your model year. Ensure the securing method is properly installed.
    ⚠This is a critical safety fastener. Proper torque and securing is essential.
    Torque spec

    Axle Nut250 Nm (184 lb-ft)
13. 13

    Refill rear differential with gear oil
    Locate the differential fill plug. Using a fluid pump or squeeze bottle, add 2.0 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 drip out. Install the fill plug and torque appropriately.
14. 14

    Reinstall wheels and lower vehicle
    Install rear wheels and hand-tighten lug nuts. Lower vehicle until wheels just contact the ground. Torque wheel lug nuts to specification in a star pattern. Fully lower vehicle and remove jack stands.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Ensure all fasteners are torqued to specification and locking devices (cotter pins) are properly installed
2. Double-check differential fluid level at the fill plug after vehicle has been lowered
3. Verify no tools or parts have been left in the work area

Verification

• Test drive the vehicle for 10-15 minutes to allow the differential to reach operating temperature
• Inspect the axle seal area for any signs of leakage immediately after test drive
• Re-check differential fluid level when warm and top off if necessary
• Inspect again after 50-100 miles of driving to confirm seal is not leaking
• Listen for any abnormal noises from the rear differential during operation

More procedures for this vehicle