5R55S Shift Kit 2008, new and ready to install. Fits the 5R55S. Ships fast from the USA.
A 2008 Explorer, Mountaineer or Mustang V6 whose 5R55S now slips on the 3-4 shift, bangs into gear late, or has lost engine braking on a downhill is usually past the point a shift kit can help. This listing carries a shift kit name, but the part is a new banner rebuild kit for 2008 and later 5R55S and 5R55W transmissions. It pairs a complete overhaul kit and a bonded piston with twelve Raybestos high-energy friction plates, which is what a slipping S needs once it is out of the truck.
Steel plates, bands and a filter are not part of this kit. Plan on reusing good steels or buying them, and add a filter at assembly.
Sonnax's "Figuring Out the 5R55 Alphabet" explains the slow failure on the W and S. The TCC modulator and main regulator bores wear first, then the three VFS modulator bores wear with city cycling, and clutch and servo pressure falls. The adaptive strategy in the PCM covers for it for a while, then gear ratio codes or real slippage show up. By then the direct and forward frictions have been slipping under low apply pressure for thousands of miles. The same article notes that early Mercon V factory fill, used before May 2005, degraded solenoids; a 2008 build came after that change, so on these trucks friction wear and bore wear are the more common story. Transmission Digest's look at 5R55S/W engagement adds that the unit runs four on/off shift solenoids, a PWM converter clutch solenoid and three variable force solenoids, so pressure faults have plenty of places to start.
Pull the pan. Clean fluid with a solenoid code points to the solenoid body or the valve body, not this kit. Our 5R55S 3-4 clutch failure guide covers how a direct clutch slip shows up on a scan tool, and the harsh or delayed shifts walkthrough separates pressure faults from worn frictions. Also check the case servo pin bores; worn bores make the bands slip no matter how fresh the clutches are.
This listing is for 2008 5R55S units, and the kit is made for 2008-up S and W transmissions. Sonnax notes the W ran in 2002-2003 Explorers and Mountaineers before the S took over from 2004, and the S also replaced the N in the Lincoln LS and Thunderbird for 2003. For a 2008 the S sits in the Explorer, Mountaineer and Mustang V6. Count teeth on your old frictions (48 direct, 89 forward, 16 overrun) before you scrap them. Not sure which unit you have? Our 5R55S identification guide helps, or send us the year and VIN. Everything else we stock for the family is on the 5R55 collection page.
| Fits | 5R55S 2008 |
| Part type | Shift Kit |
| 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.
No. Despite the listing name, it is a banner rebuild kit: an overhaul kit with a bonded piston plus twelve Raybestos frictions for the direct, forward and overrun clutches.
No. Reuse steels that are flat and not heat-blued, check the bands, and buy a new filter and pan gasket for assembly.
The kit is made for 2008-up 5R55S and 5R55W units. Compare tooth counts on your old frictions with the list above, or send us the year and VIN to confirm.
Loss of engine braking in a manual range often points to a worn overrun clutch. This kit includes two new 16-tooth overrun frictions along with the seals to renew that circuit.
Yes. Ford units built after 2002 use adaptive shift strategy, so clear the adaptive tables and run a relearn drive after installing the rebuilt unit.
