it's not the 4th gear that shifts too early. it's the torque converter locking up early and does it around 35mph but shafts hard at 60 or higher. it also doesn't stay locked up so that's the same problem ur havin. i just got an e-mail from the tech at escortfocus.com and they sent me the wiring diagram for the toggle switch to the lockup soleniod so i can controll that manually and keep the torque converter locked.
i also did a search on schucks.com to find out which car uses the same transmission pan gasket and filter and i'm lookin more towards the mazda mx-3 with the v6 motor so i'm guessing the valve body will fit better than the probe. with that valve body, it'll probably change the shifting points to shift at higher rpms so we'll see what happends.
here's the info i got in my email for the toggle switch that would help u and others using the automatic tranny:
this picture shows the location of the wiring
The TCC wire is the one to cut and run through a switch. The wiring can be confusing. Look at the wiring from the connector that goes back into the wiring harness, not towards the transmission plug where the wires go inside. The wire has to be the BLUE wire with a BLACK stripe. Unwrap and clean the wires if necessary so you can see the color codes. The confusing thing, there is a blue wire with a yellow stripe on each side of the connector. This is not the same wire on each side.