Put 4:10's in my 94 gt auto, now my car wont shift right please help!!!

[Capri306]

Before I move this post to Windsor Power, I'll throw in my 2 cents: I think mebbe when you replaced the speedometer drive gear, the VSS (vehicle speed sensor) signal might not be getting back to the EEC-IV. Chances are that the sensor itself was damaged, the wires aren't plugged in right, or something related to it. Correct me if I'm wrong, but the 94 GT's had the AOD-E, right? AFAIK, the VSS signals the computer as to how fast the driveshaft is rotating, and the EEC uses this and load (TPS and MAF) to determine shiftpoints. If the computer has no idea how fast the vehicle is going, it's never going to shift correctly. Does it make a significant difference how fast you're going or how far open the throttle is as to the relative shift point? Does it consistently shift at a certain RPM?