Good Morning,

So I picked up a 99 F250 SD, Vin is 1FTNF20L8XED20061

5.4l 2V Gas, with what I assumed was an 4R100 Transmission. Ended up doing a rear end swap, because the prior must have thought differential fluid levels were optional. And while I was at it, put new seals in the junkyard donor, checked all the internal bearings (The donor was a limited slip, while the old one was a open diff, put all new softlines, calipers, hard lines from middle of the truck, etc... basically anything I could think of. Fixed poorly repaired power steering lines, recharged the A/C, fixed the mess of wiring for the power seats etc... I am pretty confident in my wrenching, Until I started to diagnose the P0500 code for the output speed sensor. Looked like by what I could research that there should be one on top towards the engine, and another on the tailshaft housing. Except there is nothing in both spots. On the side of the tailshaft there is an unmachined port where it looks like the E4OD speed sensor would have gone.

Th wiring harness does not have any unused connectors, so I tend to think this was not a tranny swapped unit, IE someone put an E4OD in to replace the 4R100.

I have read that in the 99 Model Year, there was some funky stuff with different versions of transmissions being used. Like some had the older Solenoid packwithout PWM like an E4OD had (Which is what was in mine when I dropped the transmission pan to change the filter.) while the later built trucks had the PWM type solenoid pack.

I have a pic of the transmission tag if someone can point me to a cross reference page so I can decode it, or if someone has come across this type of configuration I would appreciate a pointer or two. I'm going to replace the sensor in the rear end as some information points to the output speed sensor being in the rear end, though that seems counter to what the official ford parts site indicates.

I've attached a pic of the transmission tag if anyone is familiar with reading them. This blasted O/D flashing is just irritating me, and the last thing I need to figure out.

 

Forgot to add, the spedo works fine, as does the Tach, and it shifts fairly smooth.

 

On my 99, the sensor is actually in the rear differential. I learned this because the transmission started shifting goofy. However, my speedo also misbehaved during the erratic shifts.

 

The transmission has an Output Speed Sensor.

The rear differential has a Vehicle Speed Sensor.