5R55E Planetary, new other (see details) and ready to install. Fits the 5R55E. Ships fast from the USA.
A 4.0L Ranger, Explorer, Mountaineer or B4000 with the 5R55E five-speed that howls on the highway, drops second or fifth, or shows a burnt front gearset on the bench needs a sound overdrive planetary before it goes back together. This carrier is new old stock, never installed and sold out of its original box, under interchange number A56580C (cross-referenced as 56580C and 5R5225BN). You get the planetary by itself, as shown in the photos.
The 5R55E is the 4.0L, higher-torque member of the A4LD family. Sonnax notes that Ford beefed up the drive components for the 4.0L in 1996 to create the 4R55E, then made it a five-speed in 1997 by applying the front servo for an overdriven first and fifth. The front, or overdrive, planetary is what makes that trick work: with the overdrive band applied, it turns the gear train faster than its input, at a 0.75 ratio. That is why the 5R55E's published ratios run 2.47 in first, about 1.87 in second, then 1.47, 1.00 and 0.75. Second is simply first gear multiplied through this planetary. When the coast clutch locks the gearset instead, it turns 1:1 and gives engine braking.
A lost second or fifth is not always the gears. Sonnax documents a worn coast clutch valve that vents overdrive servo release oil and applies the coast clutch, causing no second, no fifth and no engine braking in the five-speed units. A leaking EPC circuit causes flares and delayed reverse too. Check line pressure and codes first, following our 5R55 diagnostic walkthrough. If the hydraulics test good but the unit whines in the overdriven gears and the pan carries steel, pull the front unit and check the pinions for end play and heat damage.
This planetary is listed for the A4LDE, 4R44E, 4R55E, 5R44E and 5R55E in Ford and Mazda trucks. For the 5R55E that covers the 4.0L OHV and SOHC Ranger, Explorer, Mountaineer and B4000. The Ranger Station lists the 5R55E in 1998-2011 4.0L Rangers. This is not the 5R55W or 5R55S, which use a different geartrain. Running changes were made in this family, so match pinion count, splines and height against your old carrier, or send us your year and VIN to confirm it. We also stock a new 1997-2011 5R55E overdrive carrier, and the rest of the family is on the 5R55 parts page.
Use new thrust washers and bearings with the carrier, inspect the bushings, and set end play before closing the case. The 4.0L puts more load through the overdrive section than the smaller engines, so fix the hydraulic side at the same time: a 5R55E pressure control solenoid restores EPC control, and the 1997-2005 overhaul kit supplies the seals and gaskets. Flush the cooler and lines, fill with Mercon V, and drive gently while the computer relearns the shifts.
| Fits | 5R55E |
| Part type | Planetary |
| Condition | New Other (See Details) |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yes. Interchange A56580C is listed for the A4LDE, 4R44E, 4R55E, 5R44E and 5R55E. Still compare it to your old carrier before installing.
No. The 5R55W and 5R55S are a different design. This part is for the 5R55E and its A4LD-based relatives.
It can be, but a worn coast clutch valve or EPC leakage causes the same loss of second, fifth and engine braking. Test pressure and read codes before you tear it down.
The overdrive planetary carrier only, new old stock and not in its original box. Thrust washers and bearings are not included.
Mercon V. Flush the cooler and lines when you install the new planetary.
