2001 dodge 2500 4x4 auto. When I try to start off it feals like the trans is slipping and once it gets going it want shift in overdrive. Stock trans with 75000 miles truck has 300000. The filters and bands where adjusted and changed about 7000 miles ago at last oil change. Any ideas. I check the fluid in nutreal.

Sounds like it is in limp mode. Do you have any codes? Are you sure it is shifting at all and not just stuck in third gear? Sounds like you need some new solenoids or maybe the relay is bad. Take the trans relay out and switch it with the horn relay. Honk the horn. Did it honk? If so, that relay is good. Next you have to change the solenoids. Take this time to upgrade the governor pressure solenoid as well. You want to find the Borg Warner governor pressure solenoid. http://www.ebay.com/itm/42RE-44RE-46RE-47RE-48RE-HEAVY-DUTY-GOVERNOR-PRESSURE-SOLENOID-BORG-WARNER-a518-/130582959652 The transducer can remain OEM. If you do it yourself you will also need 10 quarts of atf+4.

Yes it is shifting, no codes, its done if before and if you let it sit for a little bit it went back to normal. But now it always slipping and want shift in to overdrive

Did you check the relay? Codes? There are a lot of problems that can cause what you are describing. Most of the time it is a simple solenoid replacement or you need a rebuild. Sounds bad to me.

What cajflynn said, i had the same problem and I upgraded to a borg werner governor solenoid and an oem mopar pressure transducer...do a filter change too...or the worst, your tranny is dead. Both parts are combined $150 or less