Is it a Ford 5R55N W or S?

The Ford 5 speed automatic transmission known as the 5R55N or W or S comes in 2WD and 4WD format, and is found in the following vehicles and is identified by the last letter of the transmission code.

The 5R55N is Non-Synchronous meaning that when the transmission shifts, it happens by applying only one clutch or band and no other member needs to activate or de-activate. The 5R55W & S are Synchronous meaning that when the transmission shifts, one member be it a clutch or band has to activate, and another clutch or band has to de-activate simultaneously.

Although they appear similar visually, many parts are not interchangeable including the filters.

Resetting the overdrive and

intermediate band is part of

the service procedure.

Common problems include worn servo case bores, broken servo pistons, and bands in some cases, causing gear ratio codes that are not solenoid related.



Solenoid fault codes can be fixed by replacing the solenoid block assembly or installing a shift correction kit. Other replaceable electrics are speed sensors and the manual lever position switch.

Another known fault is the failure of the pump control flow sticking causing no movement, delayed engagement, no movement until RPM increased and pump noise. Aftermarket correction kits are available to fix flow valve and codes P1740,P0732,P733,P735.

Overdrive gearset and one-way sprag failure
are also common.

All the parts required to Service – Rebuild – Modify are available from Driveline Auto Parts. Get in touch for more details.

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