Mitsubishi F4A22

Transmission general data

Standard automatic transmissions KM175-5, 176, 177-5,6,7/8 (another name- F4A21-F4А22) found application in FWD Mitsubishi cars. This transmission has been installed on Mitsubishi Galant, Sonata,...etc since 1988. It was developed on the basis of a successful 3-speed family KM170. This family of FWD automatic transmissions was actively installed on Hyundai Elantra, Sonata, Excel etc. It was also installed on budgetary cars Dodge, Plymouth, etc. The new series of 4-speed automatic transmissions named as A4AF-1 (and its modification A4AF-2, A4BF-2) was designed by Hyundai AT-department under the supervision of Mitsubishi in 1992 on the basis of КМ175 series for small cars Hyundai.

Technical issues and repair guidelines

It’s a popular series of transmissions from Mitsubishi – Hyundai and one of the most popular Mitsubishi transmissions in repair services. Owners of cars with this type of transmissions prefer a cosmetic repair by their own forces or replacement with the used transmission.

The repair kit of gaskets and seals is ordered together with the kit of friction components. Rarely, owners decide to perform a classic reassembly and additionally order the kit of steel discs. For cars with short mileages and normal pressure state in packages, it will be enough to replace the filter (for series КМ175-177) and change ATF.

Seals are usually replaced because of fluid leakages between the transmission and the torque converter unit, which is considered to be a sign of the torque converter wear-out. Bushings and all rings are replaced in order to restore the pressure in packages. Firstly, frictions burn in Forward/Direct packages (with steel discs), then its turn for friction clutches of the package Overdrive with steel discs and the Low/Reverse package. In most cases, replacement of spare parts and friction elements is accompanied with replacement of the brake band (Kick-down). The electrical mechanism of this transmission is very reliable, and only solenoids,which reached the end of their service life, should be replaced. Before solenoids replacement, it is recommended to check the wiring integrity.