Diagenic

05 expedition 4wd 100k miles
I have developed a trans problem, it seems like its slipping in D,1,2 at first i thought maybe the bands went out, reverse works fine, any forward gear does not work most of the time, if i am in a parking lot i can stop and stop as many times as i want without a problem, but when making turns and anytime i stop at a red light the truck just revs up like its in neutral, usually when i rev it up to 3-4k i can get it to start rolling and then everything works fine. I had O/D light come on and go off after a minute or so, no check engine, then yesterday check engine finally came on and I got the P0720 codes, prior to the engine light coming on. when the o/d would blink and go off without a check engine. Does it sound like that sensor or circut will be my problem? is do you think that could be coming up as an issue because of internal wear and need a rebuild? just looking for some advice.

techrep

iTrader: (1)

I assume you have checked the fluid level and or have had it serviced.

Diagenic

Fluid level is fine, no burn smell, no iron shavings

Diagenic

Have checked the ohm resistance on the output speed sensor to be 439, since that sensor relates to p0720 code. Today i changed tranny fluid and filter to be on the safe side. Cleaned the sensor and put it back, checked the pcm connectors for dirt. Car still goes bad. When i put in drive, no clank sound as it usually does. Goes forward but revs up without the speed to match it. Speedo functions ok. Reverse gear also.

Diagenic

dropped the pan and the oil was red and clean, no dark gray goop, no metal shavings. No bad smell. Oil was changed 2500 miles ago. Changed the Oss today, reset errocodes. Same **** as before. Goes into reverse as usual, when i put it in drive it takes long time for it to engage, and then the car just rolls forward without any power. Any suggestions ?