AW5550SN Friction Transmission parts, repair guidelines, problems, manuals

Transmission general data

Number of gears Transmission Type Drive Torque (Nm) ATF (full capacity) L ATF (change) L ATF type
5 AT FWD 330 7,1 3,5 Type T-IV
Part type (1) Expand

Technical issues and repair guidelines

The torque converter repair after running 200 thousand kilometers is a routine procedure. Repair kits of gaskets and seals for this transmission are produced by many manufacturers. Frictions are replaced by whole packages. Packages of clutches and brakes are designed in a fairly balanced manner and wear out at about the same time. The complete kit of frictions is also ordered when linings of remaining (unburned) clutches are soaked with burnt oil.The most popular parts for replacement are the pump seal and the pump cover bushing. The first problem occurs when operating in the oil starvation mode and with the wornout torque converter. Almost each overhaul is accompanied with the torque converter cutting and its subsequent rebuilding. The lock-up friction lining wears out quite rapidly causing many issues in the AW55-50.


There are many signs of the faulty valve body, but the reason for the majority of premature (before 150-200 thousand kilometers) problems of the mechanical components in this transmission lies in insufficient pressure of the ATF coming from the valve body. Dirt in the ATF and high temperatures, wear out and clog channels of valves and solenoids of the valve body. Worn-out areas are clogged with dirt and plungers get wedged, so the ATF does not reach clutch packages and the torque converter lock-up.The valve body repair and cleaning should be performed as early as possible (when you notice the first signs of improper operation) in order to avoid typical and fatal problem, namely the valve body housing wear-out. For rebuilding of transmission units in "old" cars, specialists usually order the kit of frictions, steel discs, and repair kit of gaskets and seals (overhaul kit). At the same time specialists replace the brake band (because friction linings are soaked with burnt oil). The pressure shortage from oil, coming from clogged valve body may have a negative impact on bushings. The pump cover bushing is the first to wear out. In rare cases planetary gear bushings are pressed out.

Mechanical elements of the AW55-50SN transmission are very reliable or even may be called “flawless”. The evidence of reliability lies in the factor, that for 90% cases of transmission components repair, specialists order only the repair kit of bushings. But if a driver frequently overloads the transmission, then repair specialists sometimes have to rebush or replace worn-out rear planetary gear.