I have a 01 Supercrew with 4r70w transmission. Got stuck in some deep snow and mud a few months back. got pretty rough shifting back and forth before I got "unstuck:. As soon as I got back on the road noticed serious problems with transmission. the symptoms are: does not shift down into 1st or shift up to overdrive, takes off in 2nd and goes to third. if I manually pull the shift lever to low gear it is like it is completely locked,the truck wont budge an inch with acceleration. Shift it to drive and the truck will take off all though very sluggish because its taking off in 2nd. then at 55-60 mph it never goes to overdrive . od light flashes on shifter. Had a mechanic hook up a scan tool and there are no codes, the truck has just over 100k miles and the trans doesn't slip at all . in fact ive still pulled a loaded car trailer with as is and driven approx. 2000 miles since. now its spring and I can be without my 4wd for awhile so its time to fix it. . im assuming something broke internally. Any ideas would be appreciated.

 

Your mechanic doesn't have a scan tool that can read Ford transmission codes. I'd take it to a transmission shop or a Ford dealer.

 

This is one of the very rare instances where I don't recommend reading the codes. Something mechanical has failed inside the trans. The only way to know what failed is take it out and tear it down.

 

X2

Listen to Mark. I was thinking the exact same thing while reading the OP

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