Tranny trouble

I have a 1990 Jeep Cherokee Laredo, AW4 tranny. I am having this problem: It delay when try to shift from 3rd to OD, and changes between 3rd and OD. You Know, you are driving and it try to shift but it doesn´t respond and when it finally respond starts to changing between OD-3rd-OD. What could it be??

Is your engine missing?

"No, it's right there under the hood"

Check the basics - is it full of good fluid (Dexron/Mercon, not Chrysler ATF)? What size tires do you have? Larger than stock will often result in hunting gears and popping in and out of OD often.