4R70W Reaction Shell 2004, remanufactured and ready to install. Fits the 4R70W. Ships fast from the USA.
If your 2004-or-later Ford 4R70W or 4R75W came apart with a cracked sun shell, a chewed-up rear planet or metal all over the pan magnet, this is the complete gear train that goes back in. It is a remanufactured planet set built for the late-design units: a non-magnetic sun shell, the forward sun gear, the ring gear, and a heavy-duty rebuilt rear planet. Buying the late parts as one matched set matters more on this transmission than on most, because Ford changed several of these pieces for 2004 and the early and late versions do not mix.
The 4R70W is a four-speed rear-wheel-drive overdrive automatic from the AOD family, and all four forward gears plus reverse come out of one compound planetary gear set. The forward sun gear, the sun shell, the planet carrier and the ring gear are held or driven in different combinations by the forward clutch, intermediate band, overdrive band and the other clutches to produce each ratio. When a gear tooth, a planet pinion bearing or the shell gives up, every gear that runs through that piece is affected.
On the 2004-up units the gear set also does a job for the computer. ATRA's interchange notes explain that the input speed sensor reads the stamping on the forward drum through the sun shell, so the late shell has to be non-magnetic. Install a magnetic shell and you get harsh or no shifting along with ratio and input speed sensor codes. The 2004 ring gear changed too: the new output speed sensor reads the 24 extended parking pawl lugs instead of six machined holes, and ATRA says there is no interchange between early and late ring gears.
Worn intermediate bands and burned forward clutches are the 4R70W's best-known failures, and the debris they make often finishes off the planetary bearings. If a failed band or clutch pack is what took the unit apart, plan on replacing the gear set along with it.
Pull the pan and look at what is on the magnet: fine gray paste is normal wear, but flakes, bronze washer material or pieces of pinion needle bearings mean the gear train needs attention. A noise test on a lift that isolates the gear where the sound appears will tell you whether the planet set or something outside the transmission is at fault. Our 4R70W F150 common problems guide walks through the usual failure order on these units, and the Crown Victoria 4R70W problems guide covers the sun shell and speed sensor changes in detail.
This set is for 2004-and-later 4R70W and 4R75W (including 4R75E) transmissions only. Per the listing, the shell is non-magnetic with 38 teeth, the forward sun gear and rear planet have 31 teeth, and the ring gear has 88 teeth with 2 inch lugs. It will not correctly fit a 1993-2003 unit. Before ordering, confirm your transmission has the late-style output speed sensor and the input speed sensor, or send us your year and VIN and we will check it. You can see every part we carry for this transmission on the 4R70W collection page.
| Fits | 4R70W 2004 |
| Part type | Reaction Shell |
| 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.
No. It is the 2004-and-later design. The 2004 ring gear uses a different output speed sensor target and the sun shell is non-magnetic, and ATRA's interchange notes say the early and late ring gears do not interchange.
On 2004-up units the input speed sensor reads the forward drum through the sun shell. A magnetic shell blocks that signal and causes harsh or no shifts with ratio and input speed sensor codes.
Per the listing: the non-magnetic sun shell, forward sun gear, ring gear and a heavy-duty rebuilt rear planet, sold as one matched set.
Thrust bearings and washers, the filter, and the cooler or cooler flush. If the failure started with the intermediate band or forward clutch, replace those and check the pump for debris damage.
Mercon V for 4R70W and 4R75W units through 2008. Some later 4R75E applications moved to Mercon LV, so confirm against your owner guide.
