5R55S Shift Kit 2002-2010, new and ready to install. Fits the 5R55S. Ships fast from the USA.
People shopping for a 5R55S shift kit usually have the same complaint: a 2004-2010 Explorer or Mountaineer, or a 2005-2010 Mustang, that bangs into third, flares between second and third, or drops into one gear with the wrench light on. Before you order, know what this listing really is. It is sold under the shift kit name, but the parts in the box are a new solenoid block (the pack that bolts under the valve body) packaged with a new filter, a pan gasket and the valve body gasket and plate pieces shown in the photo. On this transmission that block is the first thing to suspect for most electronic shift complaints, so for many buyers it is the right part. It is not a set of valves and springs for recalibrating the hydraulics.
The 5R55S has no throttle valve cable and no governor. The PCM runs every shift through this one assembly. Transmission Digest counts eight solenoids on it: four on/off shift solenoids that select the gear, one pulse-width converter clutch solenoid, and three variable force solenoids that set pressure. ATRA's seminar notes explain that two of those pressure solenoids work against each other to raise and lower mainline, while the third controls reverse engagement and applies the direct clutch in fourth and fifth. Because a single assembly controls both gear choice and apply pressure, a worn block can cause a harsh shift into one gear and a soft, slipping shift into the next.
A true shift kit corrects worn valves and springs inside the valve body. A solenoid block fixes the electrical and pressure-control side. Start with the fluid: Mercon V, checked hot, with no burnt smell and no heavy friction paste on the magnet. Then read codes and watch commanded gear against actual gear on a scan tool. Solenoid and pressure control codes, or a fault that comes and goes with temperature, point to the block. A slip in fifth with a ratio code such as P0735 points to servo pin bore wear in the case, which no part under the pan will cure. Our 5R55 harsh or delayed shift walkthrough and the 5R55S shift solenoid symptoms guide lay out the checks in order. If testing points to worn valve bores rather than the block, the 5R55S shift correction kit is the hydraulic fix.
The listing covers 2002-2010, and the block style fits both the 5R55S and the 5R55W. The year range needs a careful read. Sonnax shows that 2002-2003 Explorers and Mountaineers used the W and that the S took over in those trucks from 2004, after first appearing in the 2003 Lincoln LS and Thunderbird. ATRA notes that 2002-2003 units left the factory with the early 1L2Z-7G391-AG pack, while 2004 and later units use the late pack, now superseded by the updated 9L2Z design. Early and late packs make slightly different pressure at the same command. For a 2004-2010 vehicle this is a direct match. For a 2002-2003 truck, read the number on your old pack, or send us the year and VIN and we will check it. The 5R55N used in 2000-2002 Lincoln LS and Thunderbird models has a different solenoid and does not take this block. The 5R55S identification guide shows how to tell the versions apart, and everything else we stock for this family is on the 5R55 collection page.
| Fits | 5R55S 2002-2010 |
| 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, the photos show a new solenoid block with a filter, a pan gasket and valve body gasket and plate pieces. If you need a hydraulic shift correction kit for worn valves and springs, see our 5R55S shift correction kit.
Yes, if the vehicle has the 5R55S five-speed. 2004-2010 units use the late pack design that this block matches. Check the tag on the case if you are not sure which transmission is in the vehicle.
Possibly. Those years were built with the early 1L2Z-7G391-AG pack, which makes slightly different pressure from the late pack. Read the number on your old block and send it to us with your VIN before ordering.
Yes. Clear the codes, reset the adaptive tables with a scan tool and drive through all five gears with a mix of light and medium throttle so the PCM can relearn shift pressure.
A pan service only replaces part of the fluid, so do not use the dry-fill figure of roughly 12.4 to 12.7 quarts listed for the 4.0L and 4.6L. Add Mercon V gradually and set the level hot at the T30 Torx check plug.
A fifth-gear slip with a ratio code is usually servo pin bore wear in the case. Apply oil leaks past the worn bore, and that needs a bore sleeve repair inside the transmission.
