Replace the front axle seal on the driver or passenger side of a 2015 Kia Forte 1.8L to stop transmission fluid leaks at the differential.

Warnings

Tools required

Parts

• Front axle seal × 1 — Use OEM specification
• Axle nut × 1 — Use OEM specification
• New cotter pin or stake washer × 1 — Per torque spec requirement

Fluids

• Kia SP-IV-M ATF — 1 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Loosen wheel lug nuts before raising vehicle
3. Raise vehicle and support securely on jack stands at manufacturer specified jacking points
4. Remove wheel from side being serviced
5. Place drain pan under transmission differential area

Procedure

1. 1

   Remove axle nut
   With vehicle still on ground or with helper applying brakes, use breaker bar and 32mm socket to remove the axle nut. This nut is very tight at 250 Nm. Remove and discard the cotter pin or unstake the nut first. Discard the old axle nut as a new one should be installed.
2. 2

   Disconnect outer CV joint from hub
   If the axle is stuck in the hub, thread the old axle nut back on a few turns to protect threads, then tap the end with a brass hammer to break it free. Remove the nut completely. The outer CV joint should now be free from the wheel hub but will still be connected to the steering knuckle via the axle shaft.
3. 3

   Remove inner CV joint from transmission
   Position drain pan directly under the inner CV joint at the transmission. Using a pry bar between the transmission case and the inner CV joint housing, carefully pry the axle shaft out of the differential. Apply firm, steady pressure. You will feel a pop as the circlip releases. Pull the entire axle assembly out of the transmission and away from the vehicle. Expect immediate fluid drainage.
4. 4

   Remove old axle seal
   Clean the area around the seal in the transmission case. Using a seal puller, slide hammer with hook, or carefully with a pry bar, extract the old axle seal from the transmission case. Work carefully to avoid damaging the seal bore in the aluminum transmission case. If using a pry bar, work around the seal evenly and avoid gouging the bore.
5. 5

   Prepare seal bore and new seal
   Thoroughly clean the seal bore in the transmission case using a wire brush and shop rags. Inspect for any damage, burrs, or scoring. Remove any debris or old seal material. Lightly coat the outer diameter of the new seal with clean ATF. Also coat the seal lip with ATF.
6. 6

   Install new axle seal
   Position the new seal squarely in the bore with the lip facing inward toward the transmission. Using a seal driver or large socket that matches the outer diameter of the seal (contacts outer edge only, not the center), carefully tap the seal into place. Drive it in evenly until it is fully seated and flush with the transmission case. Do not drive on the seal center as this will damage the sealing lip.
7. 7

   Inspect and prepare axle shaft
   Inspect the inner CV joint splines and the seal contact area on the axle shaft for any damage, wear, or sharp edges that could damage the new seal. Clean the splines and shaft thoroughly. Ensure the circlip on the inner CV joint is in good condition and properly seated in its groove. Lightly coat the seal contact area of the shaft and splines with clean ATF.
8. 8

   Install axle shaft into transmission
   Carefully align the inner CV joint splines with the differential side gear. Push the axle shaft straight into the transmission with firm pressure until you hear and feel the circlip snap into place. Give the axle a firm tug outward to verify the circlip is fully engaged and the axle will not pull out.
9. 9

   Reinstall outer CV joint to hub
   Guide the outer CV joint splines into the wheel hub. Ensure proper alignment and push the axle fully through the hub. Clean the threads on the axle shaft and install the NEW axle nut. Hand thread the nut to prevent cross-threading.
10. 10

    Torque axle nut and secure
    With vehicle on ground or helper applying brakes, torque the new axle nut to specification using a torque wrench and 32mm socket. After torquing, install a new cotter pin through the castle nut and axle shaft hole, or stake the nut per factory specification. Bend cotter pin ends to secure if applicable.
    Torque spec

    Axle Nut232 Nm (171 lb-ft)
11. 11

    Reinstall wheel
    Mount the wheel onto the hub and hand thread all lug nuts. Lower vehicle until tire just contacts ground. Torque lug nuts to specification in a star pattern to ensure even seating.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)
12. 12

    Refill transmission fluid
    Locate the transmission fill plug on the transaxle (consult service manual for exact location on this model). With vehicle level, remove fill plug and add Kia SP-IV-M ATF until fluid begins to drip from the fill hole. Install fill plug. Start engine and cycle through all gear positions, then recheck fluid level and top off if needed.

Reassembly

1. Ensure axle nut is properly torqued and secured with new cotter pin or staked
2. Verify no transmission fluid leaks around the new seal after installation
3. Check that wheel lug nuts are torqued to specification in star pattern

Verification

• Start vehicle and verify no transmission fluid leaks from the new axle seal area
• Test drive vehicle and listen for any unusual noises from the CV axle or transmission
• Recheck transmission fluid level after test drive with vehicle on level ground
• Inspect the seal area again after test drive for any signs of fluid seepage
• Verify axle nut is still properly torqued and secured

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