Jatco RE5R05A

Jatco's longitudinal five-speed for Nissan and Infiniti — in the Navara, Pathfinder, Patrol, Infiniti FX and the G35/G37.

Its defining failure is not in the transmission at all, and it is the single most useful thing on this page. On the Pathfinder and Navara the transmission cooler is inside the radiator, and when the internal wall between the two circuits fails, engine coolant enters the transmission fluid. The result is a pink milkshake, and it destroys the transmission in a very short time.

It is known widely enough to have a nickname, and the important consequence is preventative: a coolant loss with no visible leak on one of these cars is a reason to check the transmission fluid immediately, and many owners fit an external cooler and bypass the radiator circuit entirely before anything goes wrong.

Beyond that its faults are ordinary: a slip or flare from the clutch packs, and solenoid and valve-body wear producing harsh engagement or a limp mode. Both are far more likely on a unit that has run hot, which on these vehicles means towing.

The fluid is Nissan Matic-J or -S depending on the year, and it is not interchangeable with a generic ATF.