AX4N Transmission Shift Kit Valve Body Recalibration

This is the TransGo SK AX4N valve body recalibration kit, and it covers every AX4N and 4F50N built from 1995 on up - the four-speed transaxle Ford ran behind the 3.8L and 3.0L in Windstar, Taurus, Sable, Continental, Freestar and Monterey. It is a shift kit, not a rebuild kit: it changes how the valve body meters pressure so the clutches stop slipping on apply instead of just replacing worn friction.

Four specific complaints are what this kit is built around. Soft or sliding 1-2 shifts that only show up once the fluid is hot. Rough up and downshifts at light throttle, the kind that feel like the trans is hunting. Falling out of 4th gear. And the big one - front planet burn-up, which on this unit traces back to marginal lube flow to the front planetary. The kit adds positive lube to the front planet gears, which is why a lot of shops install it on every AX4N they touch even when the customer never complained about shift feel.

Install is valve body work. Pan comes down, filter and valve body come off, and the kit is installed on the bench following the printed instruction sheet TransGo packs in the box - do not skip it, the sheet is the kit. Plan on doing it while the trans is already open for a rebuild, or as a standalone fix on a unit whose clutches are still serviceable. Part number is SK AX4N.