Ford AX4N 4-Speed FWD Automatic · Ford/Lincoln · Expert rebuild service since 1987. Lifetime warranty. Free diagnostic.
1994–2007 Ford Taurus (V6); 1994–2007 Mercury Sable; 1995–2003 Ford Windstar; behind 3.0L Vulcan and 3.8L V6 engines
| Configuration | 4-speed automatic transaxle with overdrive |
|---|---|
| Gear Ratios | 1st 2.77:1 · 2nd 1.54:1 · 3rd 1.00:1 · 4th 0.69:1 · Rev 2.26:1 |
| Fluid Type | Mercon ATF |
| Fluid Capacity | 9.0 qts total, 4.5 qts service refill |
The AX4N coast clutch is unique — it provides engine braking in the lower gear positions. The coast clutch piston seal fails with age, causing loss of engine braking and eventually affecting forward gear quality.
Symptoms: No engine braking in 1 or 2 position; clunk on deceleration; eventually slip in forward gears
EPC solenoid wear causes low line pressure and clutch slip. Standard Ford solenoid failure mode.
Symptoms: P0743 or P0745; slip in one or more gears; harsh engagement
The intermediate brake clutch controls 2nd gear holding in the AX4N. Seals fail with age and fluid contamination, causing slip in 2nd.
Symptoms: Slipping in 2nd gear; no issue in other gears; band-like symptom in a clutch-to-clutch design
Full disassembly. Coast clutch piston seal and friction replaced. EPC solenoid replaced. All clutch packs replaced with new frictions. Valve body cleaned and rebuilt. Full Transtec soft parts kit. Converter flushed.
Mercon ATF every 30,000 miles. The AX4N was Ford's main FWD transaxle for over a decade — parts are readily available. Coast clutch failure is unique to this design and often misdiagnosed as a normal clutch issue.
The AX4N has a coast clutch system that provides engine braking in manual gear positions. When the coast clutch fails, drivers lose engine braking but may not notice any other shift quality issues — it's often undiagnosed for a long time.
Classic coast clutch piston seal failure. The coast clutch is engaged when you manually select 1st gear to provide engine braking. Piston seal replacement restores it.
Ford replaced the AX4N with the 6F50 and 6F35 6-speed transaxles in 2007–2009. The AX4N was a long-running, reliable unit with the coast clutch as its main weak point.
Mercon ATF — not Mercon V or Mercon LV. The AX4N predates both and uses the original Mercon specification.
$1,600–2,200. 2-day turnaround.
Free diagnostic, written estimate, lifetime warranty. Chicago's AX4N rebuild specialists since 1987.
