ATF, or transmission itself?

[new2explorer]

I am new to working on my 94 XLT so please bear with me. When in D or OD, the rpm start going up after I hit 20 mph. It won't shift up. I have tried punching the gas a couple times, and it will shift up to 3rd, but after that it won't accelerate and the rpm just goes way up. I ran diagnostics on it, and nothing shows up. When I checked the ATF the levels are a little high. Could some idiot put too much fluid in, and that is causing the problem? Unfortunately, the person who I bought the truck from put it through hell, and every couple months, something goes wrong with it. When I first bought, I took it to mechanics and I have discovered that I was billed for things that they never worked on. So, I am now in the slow process of figuring things out for myself and correcting things that should have been fixed years ago. There are also a lot of major electrical problems, but I just want to get it running proprely before I focus on the not-so-serious malfunctions. Any advice would be greatly appreciated.

 

[ma96782]

First thing....get the proper level of fluid in there. Smell it.......if it smells burnt.......change it. Look at it......if there is a tinge of black........change it.

Next, drive it......it may be too much fluid or something bigger like....trans rebuild time, servo, clutch, modulator or whatever.

Aloha, Mark