2002 Dodge Dakota Shifting

I have a 2002 Dodge Dakota with 130,000 miles on it, 360 engine, automatic transmission, and I am the original owner. About three months ago it started not shifting out of first gear correctly. I can bring the speed up to 30 mph and let up on the accelerator and then it will shift up. Once it is going it shifts back and forth in the upper gears and I can override the overdrive just fine. I have towed a trailer during this time and the transmission is as strong as before. I have the oil and filter changed as per the owners manual. Years ago the owner of our local dealer and I had a dispute over the warranty on the front brakes locking up and he asked me not to darken his door ever again so I have obliged him and would rather not change this arrangement. The shop I have used for years cannot find any problem and no codes show up on the computer. Please help me, Tim in Coos Bay Oregon.

You need a good independent transmission shop, not a general mechanic or a transmission chain shop, Have you looked for one in your area?

“I have the oil and filter changed as per the owners manual”

Do you mean on the transmission? Or on the engine? Hopefully you mean the transmission, but what does the owner’s manual say? Is it safe to assume that you have checked the transmission fluid?

Either way though, I’m pretty much with jesmed in saying that you need your best locally owned transmission specialty shop.

+2 for @jesmed.