H E L P '95 F350 a/t CC Dlly Last yr this time it would not up shift(3rd to OD) 3 different time, after about 200-300 miles each time, I would stop let it cool down and it would go for another 4 hrs or so and NOt upshift again. Got Home, code sezs vss, had a shop replace it, non ford part. Fine for 1k miles, then 4 weeks ago on my month long trip away from home it acts up again, after 460 miles, no upshift 3 to OD. So I crawl under there and the elec connector is kinda loose (side holder clips broke off) so I push it in 1/4 inch, Go 400 miles, Won't up shift again, crawl uner there, wiggle it, tie it to unit, go about 3 to 4 hundred again, and it won't up shift. Go to a shop, code sez vss, so I have a shop replace it with a New Ford part and today, I go 380 miles, 20 miles from Home and AGAIN, it won't upshift!!! It gets me home but in trafiic it fails 3 more time in the last 20 miles.. What the hell is going on??? Now several times last yr it wouldn't shift outa 1st or 2nd, just kinda freewheel, rpm's would jump then it might go in gear with a pretty loud solid Chunck! IT ALSO did that the LAST 20 MILES LAST NiTE. aCTUALLY LAST NITE IT ALL STARTED WITH IT downsHIFT OUTA od AT ABOUT 45 MPH.

 

also whats a OBDII ?

 

Did you replace pigtail to the VSS?

 

i replaced my VSS and still have the same symptoms your having. how do you change the pigtail and what part number would i ask for?

 

Wild guess, but I heard somebody say that a burned out 3rd brake light (the one on the back of the cab) could cause VSS problems

 

That is true it happen to me

 

here is the pigtail if yours is bad Amazon.com: Pico 5755PT 1993-On Ford Vehicle Speed and ABS Wheel Speed Sensor Two Lead Wiring Pigtail: Automotive

 

Naw same pigtail...Guess I should try one. think my 3rd brake lite is OK, but I remembered that I have a large hi power Welder MAGNET in the back bed. aslo my cig liter is out, someone sez it cause a OBDII problem if fuse out,but I don'r know what a obdII is ?.....

 

The pigtail could be getting losse and shortin out the speed sensor

don't know about the magnet

OBDII is were you plug in to check for codes under dash by your right knee