4F27E Transgo Shift Kit Valve Body Repair Ford Mazda

Transgo SK-4F27E valve body repair kit for the Ford 4F27E four-speed and the Mazda-badged versions of the same transaxle: FN4A-EL, FNR5 and FS5A-EL. This is the bench fix for the shift-quality complaints these units are known for once the valve body bores wear and the separator plate circuits start cross-leaking.

It targets the classic symptom set: the car starts off in the wrong gear, there is no 2nd gear at all, or the transmission skips 2nd and goes straight to 3rd. On the scan tool those show up as P0731 (incorrect 1st gear ratio), P0732 (incorrect 2nd gear ratio), P0741 (torque converter clutch circuit performance) and P0757 (shift solenoid B stuck on). Chasing those by replacing solenoids alone usually does not hold, because the real problem is pressure loss in the valve body.

The kit is installed with the valve body off and disassembled on the bench. Work clean, keep the checkballs in order, and follow the Transgo instruction sheet that comes in the box - it calls out the specific bores and passages to address for this casting. Manufacturer part number SK-4F27E.

Vehicles running this transaxle include the Ford Focus, Escape and Transit Connect, the Mazda 3, 5 and 6, and the Mazda Tribute. Confirm the transaxle tag before ordering.