Fordfan2006

So my 1995 with the E40D would drive fine but around 55 the speedo would start bouncing around so I changed the speed sensor on the diff and the wires were strung around the brake line on the diff and one of the clips to the speed sensor is broken. So I replaced the sensor and plugged it up and drove it and the speedo barley worked and wouldn't quit shifting in and out of 3rd from 2nd so I parked it and took it back apart and cleaned the dirt off the sensor and put it back together and now it works but bounces all over the place at 15 mph and up. I don't want to drive it and have it drop into first gear or something doing 40 help please..

Fordfan2006

Bump

VickMacky

Did you use a Motorcraft sensor or just an Oreilly brand sensor? These trucks are really finicky when it comes to electronics and PCV valves being MC.

fomoco998

Might have to drain rear carrier remove cover and clean the sensor ring.

Fordfan2006

advance auto is where I got it. I'll put the old one back in and see if it's how it was if it is then I know to order a Motorcraft. Sorry I just said advance IOS 10 has screwed this whole app over. Get the garage talk app it's not screwed up so you can post on your phone again!

Fordfan2006

Put the old one in and it works exactly like it did before the new one but not as bad though I cleaned it..

andretti05

Could be the gear teeth on the differential carrier inside. These may have been damaged or gunked up, making it hard for the sensor to pick up the metal as it passes. Take the diff cover off and check things out. Change the oil in there and put it back together. Could also be your PSOM in the dashboard (mini computer that is hooked up to the speedo gauge).