- The 5R55E (Ranger, Explorer through 2001, Explorer Sport and Sport Trac through 2005) comes from the A4LD; the 5R55W and 5R55S (Explorer from 2002, 2005 to 2010 Mustang) are a different design despite the similar name.
- The best-known 5R55W and 5R55S problem is wear in the case's servo bores: it slips, bangs, loses 2nd or 5th and sets ratio codes, worse when hot.
- Before replacing the solenoid body, check the connector for water and rule out the servos, the valve body or a wrong planetary: they set the same codes.
- On the 5R55E, 4R44E and A4LD, the usual problems are the bands and servo seals, front leaks (pump bushing and seal) and, on the A4LD, the modulator.
- The whole family takes MERCON V, and the 5R55W and 5R55S have no dipstick.
If your automatic Ford Explorer, Ranger or Mustang slips, loses a gear, engages reverse late or sets gear ratio codes, it most likely has a transmission from the 5R55 family. This article covers which one you have (5R55E, 5R55W, 5R55S or the A4LD the 5R55E comes from), its most documented problems according to Ford's bulletins and rebuild specialists, its trouble codes, which fluid it takes and which parts get replaced.
Which Fords have the 5R55E, 5R55W or 5R55S?
Despite the similar names, these are two different families. The 5R55E comes from the A4LD, the 4-speed automatic in the first Rangers and Explorers. The 5R55N, 5R55W and 5R55S are a different design: according to Sonnax, the base plate, solenoid body and circuits change, and only a few parts interchange with the 5R55E.
| Transmission | Speeds | Vehicles |
|---|---|---|
| A4LD | 4 | Ranger and Bronco II from 1985, 1991 to 1994 Explorer and Mazda Navajo, and the Aerostar |
| 4R44E and 4R55E | 4 | Ranger, Explorer and Aerostar from 1995; the 4R55E with the 4.0 V6 |
| 5R44E and 5R55E | 5 | Automatic Ranger and Mazda B-Series from the late nineties (5R44E with the 2.3 and 3.0, 5R55E with the 4.0 V6), V6 Explorer and Mountaineer through 2001, and the 2-door Explorer Sport and 2001 to 2005 Sport Trac |
| 5R55N | 5 | 2000 to 2002 Lincoln LS, 2002 Thunderbird and the Jaguar S-Type of those years |
| 5R55W and 5R55S | 5 | 2002 to 2010 4-door Explorer and Mountaineer (the W first and the S from about 2004; from 2006 to 2010, V6 only), Lincoln Aviator, 2007 to 2010 Sport Trac V6, 2005 to 2010 Mustang, and Lincoln LS and Thunderbird from 2003 (the S) |
Two common mix-ups: the 2007 to 2010 Sport Trac and the 2006 to 2010 Explorer with the 4.6 V8 use a 6-speed, not the 5R55S, and the automatic Mustang before 2005 is a 4-speed, not a 5R55. More detail by model in our guide What transmission does my Ford have?.
How to tell a 5R55E, 5R55W or 5R55S apart
The surest way is the tag on the transmission itself or a VIN lookup. These clues help:
- Year, engine and body: the table above rules out almost everything. A 2002 or newer 4-door Explorer has a 5R55W or 5R55S; an automatic Ranger or 2-door Explorer Sport, an A4LD, a 4R or a 5R55E.
- The dipstick: the 5R55N, 5R55W and 5R55S have no transmission dipstick; the level is checked at the pan, with the transmission hot.
- The modulator: the A4LD is the only one in the family with a vacuum modulator. Most of its shifts are hydraulic, and only the lockup (and from 1988 the 3-4 shift) is electric. From 1995, the 4R44E, 4R55E and 5R55E shift with solenoids.
- The driver's door label has a transmission code, but the same letter is reused across models: check it against the year and engine.
- The 5R55W and 5R55S look the same outside. The overdrive planetary changes: the W has a 2.41 2nd and a 0.75 5th, the S a 2.29 2nd and a 0.71 5th; the other gears are the same. If you replace hard parts, order them by VIN: mixing planetaries causes harsh shifts and ratio codes.
A common confusion: the 5R55E doesn't have a taller fifth than the A4LD's fourth. Its new gear is a second, made by applying the overdrive band in first (2.47 × 0.75 ≈ 1.86), and its 5th (0.75) is the old 4th.
Common 5R55W and 5R55S problems
These are the problems documented in Ford's technical bulletins and by rebuild specialists such as Sonnax and ATSG. Most also apply to the 5R55N.
Slips, bangs or loses 2nd or 5th: servo bore wear
This is the best-known 5R55N, 5R55W and 5R55S problem. The overdrive and intermediate servo pins work in bores in the aluminum case, and those bores wear. Pressure leaks there, the bands don't apply or release on time, and you get slips or bangs on the 1-2, 2-3 or 4-5 shifts, no 2nd or 5th, delayed reverse, burnt bands and ratio codes such as P0732, P0733 or P0735, almost always worse when hot.
The repair is in the case: sleeve or ream the bore, or replace the case. Replacing only the servo pistons doesn't fix it. With the case repaired, new servo pistons and bands go in; Sun Transmissions explains how automatic transmission bands work.
Ratio codes: not always the solenoid body
Before buying a solenoid body, rule out other causes with the same symptoms and codes: servo bore wear; valve body bore wear, such as the converter clutch modulator and main regulator bores, according to Sonnax; and, if the transmission was opened before, an overdrive planetary of the wrong version. If you replace the solenoids, Sonnax recommends priming them before installing, and since post-2002 units have an adaptive strategy, a relearn is needed afterwards; Sun Transmissions explains why a transmission needs to relearn after a repair.
Flashing light or code P0713: water in the connector
Ford issued a bulletin for the 2002 Explorer and Mountaineer with the 5R55W: the transmission light flashes and several codes set, mainly P0713, because water gets into the solenoid body connector. On 2006 to 2010 Explorer and Mountaineer and 2007 to 2010 Sport Trac with the 5R55S built through August 2009, Ford describes the same problem with water from the A/C drain: the fix is to clean the connector, apply electrical grease and cover it with a protective kit. If the connector is already damaged, there are kits to repair it.
Soft, harsh or missing 3rd on the 2002 Explorer
Ford issued several bulletins for the 2002 Explorer with the 5R55W, depending on the build date: with the 4.0 V6, soft or long 2-3 shifts at low speed and harsh 3-4 shifts; with the 4.6 V8, harsh 1-2 and 3-4 shifts at light throttle; and on units built before March 2002, no 3rd or a slipping 2-3 shift with codes P0733 and P0745.
Delayed or harsh reverse
On 2004 and 2005 5R55S units (Explorer, Mountaineer, Aviator, Thunderbird and LS built before September 23, 2004), Ford documented delayed or harsh reverse engagement. Ford also ran a US customer satisfaction program (04B22) for improperly formulated fluid that could cause that symptom over time on 2004 and 2005 5R55S, 5R55E and 5R44E units.
Goes into neutral in turns: low fluid
With no dipstick, low fluid goes unnoticed. Low on fluid, the transmission slips or drops into neutral in turns, when the fluid moves to one side of the pan. The level is set at the pan, with the transmission hot, following the manual's procedure.
Common 5R55E, 4R44E and A4LD problems
On the 5R55E, 2nd and 5th depend on the overdrive section (its band and the coast clutch), so a failing band or servo shows up on those shifts. These are the documented problems:
- Long shifts, higher RPM than expected or no shift, with the "O/D OFF" light flashing: on 1995 4R44E and 4R55E units, Ford traced it to damaged intermediate or overdrive servo seals.
- No 2nd, no 5th or no engine braking: Sonnax links it to the coast clutch valve and clutch. On the 4R44E and 4R55E, the equivalent is no 4th.
- No 1-2 or 2-3 upshift, or no engine braking in manual 1, with P0732 or P0733: Ford has a bulletin for 1995 to 2002 Ranger, Explorer and Aerostar.
- Slips, engages late or lacks pressure at wide open throttle, with P0732, P0733 or P1762: Ford linked it to low line pressure on units built before December 2001. Code databases describe P1762 as an overdrive band failure, but it isn't always the band.
- No 3rd with P0733 and a flashing light: 2004 and 2005 Ranger and Sport Trac built before September 2004.
- Delayed reverse (2001 Ranger with the 3.0 and 5R44E), or no reverse and a burnt reverse band, which Sonnax links to wear in the valve body's reverse valves.
- Servo cover leaks in cold weather (2001 and 2002 5R44E and 5R55E) and whine in 1st or 2nd (5R55E with the 4.0 V6).
- A4LD: shop experience points to heat as its worst enemy. A ruptured vacuum modulator causes harsh or erratic shifts and white smoke, because the engine draws in transmission fluid, and a failed lockup or 3-4 shift solenoid leaves it without overdrive or lockup.
Front leak: pump bushing and seal
If fluid leaks between the engine and the transmission, check the pump seal, but don't replace it alone: Sonnax links repeat front seal leaks to a worn pump bushing and a worn converter hub. Replace the bushing and seal together, and if the pump comes apart, its gasket and O-ring too. Alignment matters on assembly: Ford published information on the pump alignment tools for the 4R44E, 4R55E and 5R55E.
Common trouble codes
These are the codes that appear in Ford's bulletins for this family:
| Code | Name | What it points to in this family |
|---|---|---|
| P0713 | Transmission Fluid Temperature Sensor A Circuit High | On the 5R55W and 5R55S, Ford linked it to water in the solenoid body connector |
| P0732 | Gear 2 Incorrect Ratio | Wrong ratio in 2nd: overdrive band or servo, bore wear or low pressure |
| P0733 | Gear 3 Incorrect Ratio | Wrong ratio in 3rd; Ford ties it to no 3rd on the Ranger, Sport Trac and 2002 Explorer |
| P0735 | Gear 5 Incorrect Ratio | Wrong ratio in 5th: overdrive band or servo, or a wrong overdrive planetary |
| P0745 | Pressure Control Solenoid A | Appears with P0733 in the bulletin for the 2002 Explorer with no 3rd |
| P1762 | Ford overdrive band code | Ford linked it to low line pressure: it isn't always the band |
For what an incorrect gear ratio means, Sun Transmissions has an article on code P0730.
What fluid do the 5R55E, 5R55W and 5R55S take?
MERCON V. Ford/Motorcraft's fluid chart (version 21) lists it for the 4R44E, 5R44E, 5R55E and the 5R55N, W and S. If your manual says "MERCON", it predates the spec change: Ford asks you to use the fluid in its current chart. And don't add additives, treatments or cleaners, which Ford says not to use. The amount depends on the model and drivetrain: check your vehicle's manual.
How it's diagnosed and repaired
- Scan it with a tool that reads the transmission's codes and live data, such as fluid temperature and ratios.
- Check the fluid level and condition: on the 5R55W and 5R55S, at the pan with the transmission hot. Burnt fluid or metal debris means internal damage.
- If P0713 sets or the light flashes, check the solenoid body connector for water before replacing parts.
- On a 5R55W or 5R55S with ratio codes, check the servo bores and the valve body before buying a solenoid body.
- After repairing the transmission or replacing solenoids, do the adaptive relearn: clear the computer's memory and drive with the transmission at temperature, following the procedure.
How much does the repair cost? It depends on what failed: a connector or a seal isn't the same as sleeving the case or rebuilding the transmission. Get a diagnosis before accepting a replacement transmission.
See TSS parts for the 5R55 family
TSS parts for the 5R55E, 5R55W and 5R55S
The TSS catalog has parts for the whole family: A4LD, 4R44E, 4R55E and 5R55E and 5R55N, 5R55W and 5R55S. The most requested are:
- Intermediate and overdrive flex band (C3, A4LD, 4R44E and 5R55E): the band for the shifts that depend on the overdrive and intermediate sections. If it burned, check its servo too.
- Filters for the A4LD, 4R44E, 4R55E and 5R55E, in 2WD and 4WD versions, and for the 5R55W and 5R55S: deep for trucks and short neck for cars.
- Pump bushing, gasket and seal: for front leaks.
- 5R55W and 5R55S solenoid body, new and remanufactured, and a harness connector repair kit.
- Gold gasket kits with or without pistons, bonded servo pistons, 5R55W and 5R55S bands, clutch plates, steels, sprags and bushings.
Before ordering, confirm your transmission by year, engine and VIN, especially between the 5R55W and 5R55S. To buy online in the US, Sun Transmissions has collections for the A4LD, 4R44E, 4R55E, 5R44E and 5R55E and the 5R55N, 5R55S and 5R55W.
TSS is an aftermarket brand with OEM-comparable quality and quality control on every product. You can buy it from our authorized distributors: in the United States from Sun Transmissions, and in Mexico the full TSS catalog at Transmisiones Veinte 07.
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