5R110W Reaction Shell 2003, remanufactured and ready to install. Fits the 5R110W. Ships fast from the USA.
Read this first: the listing title calls this a 5R110W reaction shell for 2003, but what ships is a remanufactured 4x4 extension housing (the transfer case adapter) with the output shaft already installed, a new rear seal pressed in and both gaskets in the box. If your Super Duty or Excursion 4x4 is leaking fluid between the transmission and the transfer case, has a scored or cracked adapter, or you are building a TorqShift that came out of a two-wheel-drive truck and need the 4x4 rear end, this is the part you are looking for.
On a four-wheel-drive 5R110W the transfer case does not hang off a long tailshaft. Instead, a short cast housing bolts to the back of the main case and the transfer case bolts directly to it. The output shaft runs through that housing and its splined end drives the transfer case input. The housing carries the seal that keeps transmission fluid from migrating forward into the transfer case or dripping from the joint, so its bore and the shaft journal have to be smooth and round. Two-wheel-drive trucks use a different tail housing and output shaft, which is why the two are not interchangeable.
Clean the area and drive the truck, then look at where the fluid is coming from. Red or brown ATF at the housing joint and a transfer case that is overfull and smells like transmission fluid point to the shaft seal, not the transfer case itself. Check the fluid level correctly first; our 5R110 TorqShift service guide walks through the checking procedure and what debris in the pan means. If the transmission is coming out for a rebuild anyway, the 5R110 rebuild wear points guide lists what else to inspect while it is on the bench.
The housing is described for 4x4 5R110W TorqShift transmissions from 2003 on, which covers four-wheel-drive F-250, F-350, F-450 and F-550 Super Duty trucks and the Excursion. E-Series vans are two-wheel drive and do not use it. Ford made running changes to this transmission over its life, and transfer case models changed with them, so compare the bolt pattern, the shaft length and the spline count against your old parts before installing. The simplest route is to send us your year and VIN and we will confirm the match. Everything we carry for this transmission is on the 5R110W parts page.
| Fits | 5R110W 2003 |
| 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. Despite the listing title, it is a remanufactured 5R110W 4x4 extension housing (transfer case adapter) with the output shaft installed, a new rear seal and both gaskets included.
No. Two-wheel-drive 5R110W trucks use a different tail housing and output shaft. This assembly is for four-wheel-drive applications where the transfer case bolts directly to the transmission.
It is described for 2003-up 4x4 5R110W TorqShift transmissions. Compare bolt pattern, shaft length and spline count with your old parts, or send us your year and VIN to confirm.
When the seal in this housing fails, transmission fluid migrates into the transfer case. The transmission runs low and the transfer case overfills. Replacing the housing seal and refilling both units fixes it.
Use the Ford fluid specified for your truck; the factory fill was Mercon SP. Check the level hot after the repair and top off the transfer case with its own specified fluid.
