Sonnax 36948-05K E4OD/4R100 Line Pressure Modulator Valve Kit

The Sonnax 36948-05K is a line pressure modulator plunger valve and sleeve kit for the Ford E4OD and 4R100 automatics. The modulator plunger rides in an aluminum bore in the pump body, and over the miles that bore wears oval and lets the valve leak. When it leaks, the transmission cannot hold commanded line pressure, so you get low or erratic pressure, soft and delayed engagements, slipping under load, and eventually burnt clutches and bands from the low apply pressure.

This kit fits the plunger valve to a hardened, precision-ground sleeve instead of the worn factory bore, so line pressure regulation is sealed and repeatable again. The plunger measures .372 inch diameter. Because the sleeve carries the wear surface, the repair holds up instead of wearing the pump bore oval a second time.

It fits Ford E4OD and 4R100 units found behind the 7.3L Power Stroke and gas V8s in F-Series, Super Duty, Excursion, E-Series vans, and similar trucks. Installation is a valve-body and pump job: you ream the plunger bore to size with the matching Sonnax tool, then drop in the new sleeve and valve. Confirm your exact valve body and pump casting before ordering, since Ford ran several revisions across the E4OD and 4R100 run.

This is the fix for a high-mileage Ford truck that has gone soft on the shifts or is climbing line pressure codes, done right at the source instead of masking it with additives. Ships from the USA.