Frictions, steels, gaskets, and seals to overhaul the F4A41/F4A42/W4A42 four-speed automatic in Hyundai Sonata, Kia Optima, and Mitsubishi Lancer.
The F4A41, F4A42 and W4A42 are the Mitsubishi-designed four-speed transaxles that ended up under a long run of Hyundai Sonata, Santa Fe, Tucson and Tiburon, Kia Optima and Sportage, and Mitsubishi Galant, Lancer, Eclipse and Outlander models. By the time one of these reaches high mileage the complaints tend to sound alike: a flare between second and third, a slip when pulling away warm, a harsh or late reverse, or a car that drops into a fixed limp gear and stays there. When the pan comes off with dark fluid and friction paste on the magnet, the clutches are done and the unit needs a full teardown. This master kit is the box of wear parts for that job.
This family does not use bands. Every gear is made by applying a combination of hydraulic clutches and a brake: the underdrive, overdrive and reverse clutches, the low/reverse clutch and the second brake. ATSG's write-up of the F4A42 valve body describes five identical solenoids in the upper valve body, and every one except the converter clutch solenoid feeds its own pressure-control valve, so the computer controls each apply directly. That design shifts well when it is healthy, but it also means a worn friction or a leaking piston seal shows up quickly as a flare, because the computer can only command pressure; it cannot make up for a pack that will not hold. The kit replaces the frictions and steels for those packs and reseals the whole unit with new lip seals, metal-clad seals, sealing rings, O-rings and the pan gasket.
Not every F4A shift complaint is a clutch failure. Transmission Digest has covered Hyundai F4A42 cases where erratic shifts and a failsafe gear came from open or shorted solenoid circuits, and ATSG notes that a misplaced checkball or a backwards valve in the valve body can cause harsh reverse or a converter that empties. Check the fluid level and condition, read the stored codes, and test solenoid resistance at the case connector first. If the electrical side checks out and the fluid is burnt, the packs are the likely cause. Our guide on shift flare versus slip helps separate a pressure or timing problem from worn frictions, and rebuild versus replace versus reman covers whether a bench rebuild makes sense for your car.
The listing covers the F4A41, F4A42 and W4A42 four-speed front-drive transaxles in Hyundai Sonata 1999-2011, Santa Fe 2001-2009, Elantra 2003-2007, Tiburon 2003-2008 and Tucson 2005-2011 with 2.0 to 2.7L engines; Kia Optima 2001-2010, Sportage 2000-2011, Rondo 2007-2010 and Spectra 2002-2004; and Mitsubishi Eclipse 2000-2010, Galant 1999-2010, Lancer 2002-2011, Outlander 2003-2011 and Diamante 1997-2004. Several of these models also came with five-speed or other four-speed units depending on engine and year, so check the transaxle code on the case tag before you order, or send us your year and VIN and we will confirm it. You can also browse every overhaul set in our rebuild kits category.
Soak the new frictions in the correct fluid before assembly. These units take SP-III type ATF (Hyundai/Kia SP-III or Mitsubishi Diamond SP-III); do not substitute an SP-IV fluid meant for the later six-speeds. Air-check each clutch and the second brake after you stack them, and measure every pack clearance against the service manual before the unit goes back together. Hold new seals in place with an assembly gel such as TransJel rather than petroleum jelly. The kit does not include the filter, hard parts, gears or the torque converter, so inspect the drums, bushings and pump while it is apart. If the valve body is worn or the solenoids have tested weak, this is the time to fit the F4A41 solenoid kit with harness. Flush the cooler and lines so old debris does not go straight into the new clutches, then clear codes and drive through all four gears so the computer can relearn shift timing, as explained in our adaptive relearn guide.
| Transmission | F4A41, F4A42, W4A42 four-speed automatic (FWD) |
| Fits Hyundai | Sonata 99-11, Santa Fe 01-09, Elantra 03-07, Tiburon 03-08, Tucson 05-11 (2.0-2.7L) |
| Fits Kia | Optima 01-10, Sportage 00-11, Rondo 07-10, Spectra 02-04 |
| Fits Mitsubishi | Eclipse 00-10, Galant 99-10, Lancer 02-11, Outlander 03-11, Diamante 97-04 |
| Includes | Clutch frictions and steels, pan gasket, lip seals, sealing rings, metal-clad seals, O-rings |
| OE Reference | W4A42 / F4A41 / F4A42 |
| Not Included | Steel hard parts, gears, torque converter, filter |
| Item Weight | 5.96 lb |
| Ships | From the USA |
It is built for the F4A41, F4A42 and W4A42 four-speed transaxles. Many Hyundai, Kia and Mitsubishi models in the fitment list also came with five-speed or different four-speed units, depending on engine and year. Check the code on the transaxle tag or send us your year and VIN before ordering.
Friction plates and steels for the clutch packs, the pan gasket, lip seals, metal-clad seals, sealing rings and O-rings. It does not include the filter, hard parts, gears or the torque converter.
SP-III type ATF, such as Hyundai/Kia SP-III or Mitsubishi Diamond SP-III. Use it to soak the frictions and to fill the unit, then confirm the level hot.
Not always. A failsafe gear can come from a solenoid or wiring fault as easily as from slipping clutches. Read the codes and test the solenoid circuits first. If they pass and the fluid is burnt, a full rebuild with this kit is the usual fix.
A new filter, and the solenoids or valve body if they have tested weak. Inspect the drums, bushings and pump while the unit is apart. Flush the cooler before you reinstall the transaxle.
Yes. Clear the codes and drive through every gear several times so the computer can adapt to the new clutches. Some models need a scan tool to reset the adaptive values first.
