Ok, fellas, heres one for ya.

1995 EB 4X4 351
E4OD (Metric) Auto Trans

My truck runs great and shifts very smoothly when the speedo is working. (Well when it's jumping around the cluster) When the speedo stops working, the trans shifts hard and slips. I was told by the dealer that my cluster needed to be replaced. So I ordered a cluster and installed and nothing changed. The speedo is dead and trans still shifts hard. I replaced the speed sensor in the rear end and that didn't help either.

The guy at Oreilly's is telling me that there is another speed sensor located on the trans (Motorcraft - Speed Control Sensor Part # DY588), but from what I've read that may not be true.

I'm at a loss fellas. What is causing the speedo to not function properly?????

Thanks guys!!

 

The VSS, Vehicle Speed Sensor, is what sends the message to your computer what your speed is which in turn tells the trans when to shift and your speedo what speed you're going. I think the sensor is on top of the trans but don't remember exactly. I never got around to doing mine.

 

'92-'96 does not have the extra sensor on the trans, and even the ones that do have it doesn't give the signal to the speedometer or computer.

The wires to the VSS are a common problem too.

 

Really? Wow, I just screwed that up lol

 

His vss is on top of the diff and will screw with shifting. Been there, done that.

 

Meant to put this in...scan your codes, may tell you which sensor is bad

 

And if it helps, the overdrive light flashes on and off at times.

 

Yea, it'll do that.