5R55W Shift Kit 1999-2007, new and ready to install. Fits the 5R55W. Ships fast from the USA.
A 2002-and-later Explorer or Mountaineer with the 5R55W that will not move when hot, howls from the front of the transmission, or loses converter lockup on the highway has three different complaints with one thing in common: they all trace back to hydraulic parts that TransGo redesigned in this kit. This is the new TransGo SK 5R55W, the basic valve body repair kit for the W, S and N five-speeds. It is the kit a shop drops in while the pan, valve body and pump are already apart, so the rebuilt unit does not come back with the same faults the original one had.
TransGo's own instruction sheet sums the kit up as being about won't move, pump noise, no lockup when hot, slip, shudder and codes. Each fix is a specific part:
Gear ratio codes on a W do not automatically mean the valve body. The overdrive and intermediate servo pin bores in the case wear on these units, and once they leak, the bands burn no matter which kit is installed. TransGo's sheet tells the installer to wiggle the OD servo pin and confirm it is tight. Read our 5R55W/5R55S servo pin bore wear guide before you order, then follow the 5R55 harsh or delayed shift walkthrough to sort pressure, solenoid and mechanical faults. If lockup is the only complaint, our 5R55W P1744 diagnosis covers when the converter really is to blame.
This listing is titled for the 5R55W from 1999 to 2007, and TransGo lists the SK 5R55W for the W, S and N from 1999 on. In practice the W itself did not appear until 2002: Sonnax's history of the family places it in the 2002 Explorer and Mountaineer, with the N in earlier Lincoln LS, Thunderbird and Jaguar S applications. The kit carries separate instructions for the N valve body, which has a bottom plate, and for the W and S valve body, which does not, so check yours when the pan is off. If you are unsure which unit you have, send us the year and VIN before ordering. All 5R55 parts are in our 5R55 transmission collection.
TransGo states plainly that this is not a do-it-yourself kit; it is meant for experienced transmission technicians, because it involves pump alignment, valve removal and the lockup bushing. Keep removed parts in order and work one bore at a time. On reassembly, adjust the overdrive and intermediate bands snug, back off two turns and lock them, with the servo struts' short side toward the valve body. Fill with Mercon V. TransGo's level check is done with the vehicle level, engine running, in Park and the fluid between 80 and 120 degrees F, adding fluid until a steady stream runs from the check hole. Since the pump is open anyway, a worn pump body is best replaced with our 5R55W pump assembly for 2002-up Explorers, and an original solenoid pack can be swapped for the updated 9L2Z-7G391-AA solenoid block.
| Fits | 5R55W 1999-2007 |
| Part type | Shift Kit |
| Condition | New |
| Brand | TransGo |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yes. TransGo lists the SK 5R55W for the 5R55W, 5R55S and 5R55N from 1999 on, which covers the W in the 2002 and later Explorer and Mountaineer. Check the valve body for a bottom plate, since the instructions differ for the N.
It addresses the most common hydraulic cause. The factory pump flow control valve sticks and causes a won't-move condition, and the kit replaces it with an upgraded assembly. A burned forward clutch or a worn servo pin bore still needs its own repair.
Not always. TransGo states that lockup problems on this unit are usually valve body caused, and the kit includes a new lockup valve, bushing and inner valve. Rule out the converter clutch with the diagnosis guide before replacing it.
TransGo says this kit is for experienced professional transmission mechanics. Several steps require removing the pump and valve body, so it is normally installed during a rebuild or a valve body overhaul.
Use Mercon V. Check the level with the engine running in Park, vehicle level and fluid between 80 and 120 degrees F, filling until fluid runs out of the check hole in a steady stream.
