5R55W Master Rebuild Kit 2002-2007, new and ready to install. Fits the 5R55W. Ships fast from the USA.
If your 2002-2007 Ford Explorer or Mercury Mountaineer has started flaring on the 2-3, dropping second or fifth, or slamming into reverse after it warms up, and the fluid in the pan is dark with friction material in it, you are past the point where a single solenoid or a fluid change will help. This 5R55W master rebuild kit is built for that job. Beyond the usual gaskets and seals, it brings the parts that actually wear out in this unit: a Raybestos friction clutch module (RCP96-139) and steel module (000429), a forward clutch bonded piston, two Borg Warner high-energy intermediate and overdrive bands (10736BW), the Borg Warner low/reverse band (10711BW), a new solenoid block (9L2Z-7G391-A), a Transgo shift kit (SK5R55W), a filter and a pump bushing.
The 5R55W is a band-heavy design. It uses three bands, three multi-plate clutches and two one-way clutches, with the overdrive band working in second and fifth and the intermediate band working in third. That is why a tired W loses second, third or fifth before anything else, and why a kit that leaves the bands out only does half the job. This kit renews all three bands along with every friction and steel, reseals the unit with the overhaul gasket and seal set, and replaces the solenoid block that controls shift timing and line pressure. The Transgo kit recalibrates the valve body so the new bands and clutches are applied firmly instead of being slipped on.
Pull the pan first. Clean fluid and a clean magnet usually mean the problem is electrical or in the valve body, and a 5R55W valve body for 2002-2008 or a solenoid block alone may fix it. Band material and dark fluid point to a rebuild. Before you buy this kit, though, read our guide to 5R55W/5R55S servo pin bore wear. Sonnax documents that wear in the case bores feeds both the overdrive and intermediate servos, so new bands burn again quickly if the bores are oval. Measure them and plan for a sleeve repair if they are worn. The 5R55 harsh and delayed shift walkthrough covers the pressure tests in order.
This listing covers 5R55W transmissions from 2002-2007. Sonnax places the W in 2002-2003 Explorers and Mountaineers, with the 5R55S taking over in later trucks, so check the tag on the side of the case before you order rather than going by model year alone. The friction module, bands and shift kit are shared with the 5R55S. The overdrive planetary is not, but that hard part is not in this kit. The solenoid block is the main thing to check. ATRA's seminar notes say 2002-2003 units left the factory with the early pack (1L2Z-7G391-AG) and 2004-on units use the late pack, which Ford supersedes to the 9L2Z design included here. On a 2002-2003 truck, compare the number on your old block, or send us the year and VIN and we will confirm before it ships. Everything else for this family is on our 5R55 transmission parts page.
| Fits | 5R55W 2002-2007 |
| Part type | Master Rebuild 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.
The clutches, bands, seals and shift kit fit, but the included solenoid block is the late 9L2Z design. ATRA notes that 2002-2003 units used the early 1L2Z-7G391-AG pack, so check the number on your old block or send us your VIN before ordering.
The soft parts, bands and shift kit in this kit are shared between the W and the S. What differs is the overdrive planetary: Sonnax identifies the W by a 24-tooth overdrive sun gear and the S by a 38-tooth one. That gear is a hard part and is not in either kit.
Check the servo pin bores in the case, the pump, the drums and the internal harness. Have the torque converter serviced or replaced, and flush the cooler lines. A kit cannot fix worn servo bores, and those cause most repeat band failures.
Mercon V. The installation guide gives roughly 12.4 to 12.7 quarts dry behind the 4.0L and 4.6L engines. Set the final level hot through the fill plug.
Only if the cause is the burned band. P0735 is a fifth-gear ratio error, and on this unit it often comes from servo pin bore wear in the case. Measure the bores and repair them during the rebuild, or the code can return.
