- Author: Wayne Colonna
- Subject Matter: 5R55W/S
- Issue: Slipping
A 2006 FORD Explorer with a 4.0 engine using the 5R55W/S type transmission came back to Jeremy at Warren Transmissions 8 months after the original rebuild. The customer stated that all was good prior to climbing a hill when it felt like he was losing power and the engine began to rev quite high like the trans was slipping. Customer said he managed to nurse it home.
When brought to the shop, truck would barely move if even if you revved the engine. The pan was clean when dropped, but the ATF was black and had a nasty stink of converter failure.
The unit was completely disassembled but had no internal hard part, clutch or seal damage evident. The converter was badly burnt and the paint was peeling off.
The oil cooler was checked and flushed to verify proper operation with no problems found. Transmission was completely cleaned, reassembled and installed with a new converter and seemed to be engaging and shifting normally on the lift with the wheels off of the ground but it still would not pull with the wheels on the ground.
Checks were then made with the TRS and speed sensor with a scan tool and all seemed to be functioning properly. At a stop in gear, the TSS, ISS and OSS read zero. The TSS did show RPM when the engine was revved in Park or Neutral and would stop when shifted into gear indicating the clutch and gear train were holding. Oil pressure was good and it did feel like it engaged but still no pull. Scan tool data for the TSS would seem to indicate the problem was still with the converter not turning the input shaft.
Jeremy pulled the valve body and exchange it with another one. Removing valves out of the valve bodies in the 5R55E, and the 5R55S/W transmissions can be very difficult. Sometimes damage to the valve body takes place when trying to do so. Putting in a different valve body resolved the problem. Once this became a confirmed fix, the malfunctioning valve body was disassembled for inspection. If it became damaged along the way by pulling out valves, it was headed for the trash anyway. After pulling a couple of the easier valves out, Jeremy found that the Converter Clutch Control Valve Spring was in several pieces. After 13 years this spring reached a season of collapse, which prevented the converter from having its proper supply of fluid. Not the spring season one looks forward to.