E4OD Planetary, remanufactured and ready to install. Fits the E4OD. Ships fast from the USA.
If your E4OD-equipped F-250, F-350, Bronco or E-Series van has started to howl at highway speed, dropped out of overdrive after a long pull with a trailer, or left bright metal on the pan magnet, the planetary is near the top of the suspect list. This is a remanufactured planetary assembly for the Ford E4OD, the electronic four-speed Ford built from 1989 until the 4R100 took over. The photo shows a pinion carrier with helical gears and a splined hub, together with the ring gear it runs inside. Buying it remanufactured means the carrier has already been inspected and set up, so you are not betting a rebuild on a used gearset with an unknown heat history.
The E4OD is essentially a C6 gear train with an electronic overdrive unit added at the front of the case. That gives it three planetary gearsets. The overdrive set comes first. According to the ATRA clutch and band chart, the overdrive one-way clutch holds it at 1:1 in 1st, 2nd and 3rd in Drive, the coast clutch locks it for Reverse, the manual ranges and engine braking with overdrive cancelled, and the overdrive clutch holds the overdrive sun gear to produce 4th. Behind it, the forward and reverse sets share one sun gear and produce the 2.71, 1.54 and 1.00 ratios, with 0.71 in overdrive and 2.18 in Reverse.
Each carrier holds its pinions on pins and needle bearings, with thrust washers at each end. None of that hardware tolerates a lack of oil. Sonnax traces E4OD overdrive planetary failure to the plastic front lube/drainback valve: at high fluid temperature its ball seat can melt and restrict the front lube circuit, and the overdrive planet then runs short of oil.
Rule out the cheap causes first. A no-4th complaint can also be electrical: on these units, a failed solenoid circuit can hold the truck in the wrong gear, and an overdrive cancel switch fault changes how the unit shifts. Pull codes and check the solenoid pack before you decide the gears are gone. Our E4OD shift solenoid guide covers resistance checks. If the codes are clean, drop the pan. Friction dust alone points at clutches; needles, washer material or chunks of gear tooth point at a planetary. Once the unit is apart, rotate each pinion by hand and check for roughness, pitting and excess end play. The E4OD common problems guide explains the overheated overdrive pattern in more detail.
The listing is for the E4OD, which ran from 1989 through the 1997 model year and into some 1998 applications before the 4R100 replaced it. That covers heavy F-Series pickups, the Bronco and E-Series vans with big gas engines and the 7.3L diesel. The listing does not state the Ford part number or which of the three gearset positions is included, so compare it with your old part before you install it: pinion count, hub spline count, ring gear tooth count and overall height must all match. If you are not sure, send us your year and VIN and we will check it. Browse the full E4OD and 4R100 parts collection for the other hard parts in this unit.
| Fits | E4OD |
| Part type | Planetary |
| Condition | Remanufactured |
| 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.
The listing does not name the position, and the photo shows a carrier and ring gear. Compare pinion count, spline count and height with the part you removed, or send us your year and VIN before ordering.
Sonnax links E4OD overdrive planetary failure to the plastic front lube/drainback valve. At high fluid temperature it can melt and restrict lube oil to the overdrive section. Towing heat makes it worse.
The E4OD and 4R100 use the same gear ratios and basic gear train, but Ford made many component changes in 1998. Match the old part dimensions before assuming interchange.
Use MERCON V ATF. Original MERCON is no longer produced, and MERCON V is the current service fluid for Ford units that originally used MERCON.
Replace the thrust washers and bearings on both sides, the filter, and all seals and gaskets. Inspect the shells and drums, flush the cooler, and fix any lube problem that caused the failure.
