F4A41/F4A42/W4A42 Master Rebuild Kit Hyundai Kia Mitsubishi

Master overhaul kit for the Mitsubishi-designed F4A41, F4A42, and W4A42 four-speed automatic, the transaxle Hyundai, Kia, and Mitsubishi shared across a wide run of front-drive cars from the late 1990s into the 2010s. If your 2.0 to 3.5L Sonata, Santa Fe, Optima, Sportage, Eclipse, Galant, Lancer, or Outlander is slipping, flaring on the 2-3 shift, or coding up after high mileage, this is the parts set that takes the unit back to a clean baseline in one box.

The kit carries the full clutch pack rebuild: friction plates and steels for the underdrive, overdrive, reverse, and low-reverse clutches, plus the complete gasket and rubber. That means the pan gasket, all lip seals, sealing rings, metal-clad (metal-backed) seals, and the O-rings that go back into the valve body and pump. It is sized to rebuild the whole transaxle rather than patch one circuit.

On the bench, air-check each clutch drum after you stack the new frictions and steels, and set clutch clearance to the service spec before the pistons go back in. Soak new frictions in ATF SP-III (or the Hyundai/Kia SP equivalent) before assembly so they do not glaze on first apply. Replace the pump and case metal-clad seals while the unit is open, since they are the common leak points on this family.

OE reference W4A42 / F4A41 / F4A42. Fits a long list of years and engines noted in the specs, all sharing this four-speed. Steel hard parts, gears, and the torque converter are not included; this is a soft-parts and clutch master kit for a full teardown rebuild.