Ford 5R55E / 5R55S

Ford's rear-drive five-speed — in the Explorer, Sport Trac, Ranger, Mountaineer and Aviator, and in the Jaguar S-Type.

A Jaguar with a Ford truck transmission is the sort of thing nothing on the car tells its owner, and it changes where the useful information is: the S-Type's 5R55N and 5R55S have a very large American service literature filed under Explorer and Ranger.

Its recurring failure is the servo bore. The aluminium case wears where the servo piston travels, line pressure escapes past it, and the result is a delayed or missing 2–3 change and a slip that gets worse as the transmission warms up. Sleeving the bore is a recognised repair and is far cheaper than a replacement — but only while the bands and clutches are intact, which is the argument for acting early.

The solenoid pack accounts for most of the rest, producing harsh engagement or a limp mode, and it is a bolt-on part behind a symptom that reads as catastrophic.

The letters are not decoration: E is the electronic four-wheel-drive version, N and S the later Jaguar and Explorer units with different valve bodies. A procedure written for one does not necessarily describe another.