4R70W Sun Shell 1993, new and ready to install. Fits the 4R70W. Ships fast from the USA.
The 4R70W first appeared in 1993, and the oldest units are now the ones turning up with a split sun shell: a Lincoln Mark VIII or Town Car that pulls away in first, then flares with no second and no overdrive, or an early F-Series truck that has quit backing up. This is a new OEM sun shell listed for the 1993 4R70W, the early design that matches the original bearing and forward sun gear in those first-generation units.
The 4R70W is Ford's wide-ratio rework of the AOD-E, with numerically higher first, second and Reverse ratios. All of them come from one compound gearset with two sun gears. The shell is the stamped drum that carries the reverse sun gear, with tabs that lock into the reverse clutch drum. In Reverse that clutch drives the shell for a 2.32:1 ratio. In second it is held for 1.55:1, and in overdrive the overdrive band holds the same drum for 0.70:1. On a 1993 unit the second-gear hold goes through an intermediate one-way roller clutch; Ford only switched to the mechanical diode in 1998.
ATRA's interchange notes explain what changed after this part was designed. From 2004 Ford thickened the metal at the base of the gear to stop cracking and lowered the gear-to-bearing height by about .030 in. to fit a thicker two-piece bearing. That means the late shell is not a drop-in for a 1993 transmission: ATRA says the shell, bearing and forward sun gear must be changed as a set, or end play comes out wrong. If your original bearing and forward sun gear are good, an early shell like this one keeps the stack-up correct without buying the whole late set.
A 30-year-old unit can also lose second from a worn intermediate clutch or a slipping roller clutch, and lose fourth from a tired overdrive band or servo. Check the fluid condition, read line pressure, and look at the magnet. The F-150 shift problems guide covers the pressure and electrical checks, and the Crown Victoria common problems guide covers the Panther-platform cars, which share this transmission with the Town Car. If there is steel rather than friction material in the pan, the gear train needs to come out.
Listed for 1993. That year the 4R70W went into the Lincoln Mark VIII, Lincoln Town Car and F-Series. The 1993 Crown Victoria and Grand Marquis used the AOD-E, which has different ratios, and the Mustang still used the AOD, so confirm which transmission you have before ordering. Early units from 1993 through 1997 also use the white transmission connector with wiring built into it, a quick way to tell an early case. Match the height, tab count and gear teeth to your old shell, or send us your year and VIN. The 2004 4R70W sun shell is the late design, and everything else is in the 4R70W collection.
| Fits | 4R70W 1993 |
| Part type | Sun Shell |
| Condition | New |
| 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.
Probably not. The 1993 Crown Victoria and Grand Marquis used the AOD-E, which has different gear ratios. Check the tag on your case; this shell is listed for the 1993 4R70W used in the Mark VIII, Town Car and F-Series.
Only as a set. The 2004-up shell is about .030 in. shorter at the bearing surface and uses a thicker bearing, so ATRA says you must also change the bearing and forward sun gear. An early shell like this one matches your original parts.
The shell carries reaction torque in second, overdrive and Reverse, and stress concentrates at the base of the gear. High mileage, towing and harsh engagement all add to it, which is why Ford later thickened that area.
Inspect the bearing, forward sun gear, roller clutch, reverse drum tabs and planet carrier. Replace the filter and any frictions with steel in them, and flush the cooler.
Use MERCON V. Ford recommends MERCON V for vehicles that call for MERCON V or the older MERCON, and warns against using it where Type F or MERCON LV is specified.
