Ford 6F55 6-Speed FWD Heavy-Duty Automatic · Ford/Lincoln · Expert rebuild service since 1987. Lifetime warranty. Free diagnostic.
2008–2019 Ford Taurus SHO (EcoBoost), Taurus (3.5L); 2009–2019 Ford Edge (EcoBoost); 2009–2019 Lincoln MKS (EcoBoost); 2011+ Ford Explorer (3.5L EB)
| Configuration | 6-speed FWD/AWD automatic — heaviest-duty FWD Ford 6-speed transaxle |
|---|---|
| Gear Ratios | 1st 4.48:1 · 2nd 2.87:1 · 3rd 1.93:1 · 4th 1.45:1 · 5th 1.00:1 · 6th 0.74:1 · Rev 2.93:1 |
| Fluid Type | Mercon LV ATF |
| Fluid Capacity | 10.0 qts total, 5.5 qts service refill |
EcoBoost-equipped applications put significantly more torque through the 6F55 than naturally-aspirated versions. Solenoid body wear is accelerated on EcoBoost models.
Symptoms: Erratic shifts under boost; limp mode; P0750-series codes
TCC shudder under high-torque EcoBoost conditions is more severe and harder to resolve with fluid alone than in naturally-aspirated applications.
Symptoms: Shudder at 40–60 mph, often worse under boost; may trigger check engine light
AWD 6F55 units (Taurus SHO, MKS EcoBoost) develop differential carrier bearing noise at high mileage from the torque demands of the EcoBoost.
Symptoms: Growl or hum from transaxle that increases with speed; worse on turns
Full disassembly. Solenoid body replaced with updated unit. TCC replaced. AWD differential carrier bearings inspected and replaced. All clutch packs replaced. Full soft parts kit. Converter flushed.
Mercon LV every 40,000 miles. EcoBoost applications should service every 30,000 miles due to higher torque loads. The 6F55 in SHO applications benefits from an aftermarket transmission cooler.
Not normal. TCC shudder under boost is typically the solenoid body or torque converter. Start with fresh Mercon LV; if that doesn't resolve it within 500 miles, the solenoid body needs replacement.
Reasonably — with regular Mercon LV service. The EcoBoost torque is at the upper limit of the 6F55's design capacity. We recommend service every 30,000 miles on SHO and MKS EcoBoost vehicles.
10 quarts total. We use a flush machine for the complete service to exchange all 10 quarts, not just the pan drain.
2–3 days.
Yes — we rebuild 6F55 units regularly. Solenoid bodies and rebuild kits are in stock.
Free diagnostic, written estimate, lifetime warranty. Chicago's 6F55 rebuild specialists since 1987.
