Replaced the speed sensor on the rear diff with a new ford one a few months ago and it stopped. Now it's back in safe mode shifting hard 1-2 and reverse and not shifting at the right time in every other gear. It's a 1995 5.8 E40D 4x4 the fluid is bright pink and doesn't smell burnt or anything. The tail lights and brake lights all work as they should and I changed the diff fluid when I replaced the sensor. The speedo wobbles around 45-65 so I'm kinda thinking the wiring to the sensor. What else should I look for? I hooked it up to my mechanics scan tool and it pulled 0 codes. So I don't even have a code to go on. https://m.youtube.com/watch?feature=...&v=6enm308LpPk that's drive to reverse brakes floored.

 

Wow I have a firm 1-2 shift sometimes but that seems very hard. Have you checked the TPS and the MLPS sensors?

 

I've checked it in the past and it was okay. And mlps? What are those?

 

It's sometimes called a neutral safety switch. It's a sensor right on the side of the trans where your shifter is.

 

Doesn't that also control the reverse lights?

 

It does but it can still be a little out of adjustment and still have working break lights. Also, you have a 95 so you should have the upgraded connector for the switch but I would check just to make sure.

 

The wobbly speedo is bound to hurt the shifting. The new vss could have iron filings on it. Try cleaning it. And check the wires to it.
Problem could be a failing PSOM (speedo) as well. Basically, the PSOM is a mini computer that tells the main computer a bunch of info (VSS, Rabs, cruise control) it needs to determine when to shift. So if anything is wrong in the speedo or it's input it's not going to shift right.
E4OD is also very sensitive to TPS signals so that has to be right too.

 

It shifted fine without a speedo after I got it. Haha and the cruse control doesn't work anyway.. but I'll try cleaning it off when it's not raining and crap. I'm thinking it's the wiring to the sensor. It's wrapped around the sway bar pretty much..

 

So I cleaned the sensor and it's fixed...

 

2 days later it's doing it again. Not as bad but it's doing it, I'm going to clean the sensor again and see if it clears up