Ford 5R55N 5-Speed Automatic · Ford/Lincoln · Expert rebuild service since 1987. Lifetime warranty. Free diagnostic.
2002–2005 Ford Thunderbird; 2002–2006 Lincoln LS (V6 and V8); behind 3.9L V8 and 3.0L V6 engines in these luxury/sport applications
| Configuration | 5-speed automatic with overdrive — longitudinal FWD/RWD sport sedan variant |
|---|---|
| Gear Ratios | 1st 3.22:1 · 2nd 2.29:1 · 3rd 1.55:1 · 4th 1.00:1 · 5th 0.71:1 · Rev 3.00:1 |
| Fluid Type | Mercon V ATF |
| Fluid Capacity | 12.5 qts total, 5.5 qts service refill |
The 5R55N servo bore wears in the same pattern as other Ford 5R55 units — oval bore prevents band apply and causes 2nd-gear slip.
Symptoms: Slip in 2nd gear; band adjustment has no effect; servo bore confirmed worn on test
EPC failure pattern identical to rest of 5R55 family.
Symptoms: P0745; intermittent clutch slip; harsh engagements
The 5R55N TCC in the Thunderbird and LS is prone to shudder at 40–55 mph under light throttle, often caused by degraded Mercon V that no longer maintains the lockup clutch properly.
Symptoms: Vibration at 40–55 mph under light throttle; clears under hard acceleration; worse in warm weather
Same 5R55 rebuild procedure. Servo bore measured and Sonnax oversize piston installed if worn. TCC inspected and replaced. EPC solenoid replaced. Full clutch packs, soft parts, and valve body service.
Mercon V every 30,000 miles. TCC shudder in early miles is often resolved with a fluid change alone — the Thunderbird and LS are especially sensitive to fluid quality. Do not delay service on these cars.
Classic TCC shudder signature — start with a Mercon V fluid flush. Resolves in ~60% of cases. If it persists, the torque converter lockup clutch needs replacement.
2002–2005 Thunderbird behind the 3.9L V8. The T-bird is one of the rarer applications for this unit.
Different application (luxury RWD sedans/sports cars vs. performance Mustang), but core internals are shared. Torque converter flanges differ.
$1,700–2,300. The Thunderbird and Lincoln LS are specialist vehicles and parts are still available through Sonnax and Transtec.
Yes — we rebuild all Ford 5R55 variants including the 5R55N. 2-day turnaround.
Free diagnostic, written estimate, lifetime warranty. Chicago's 5R55N rebuild specialists since 1987.
