Transmission shift problem

'87 Cherokee auto trans.,feels like it's trying to engage the overdrive but it won't. At steady gas pedal appication it gets it and loses it, like an up-and-down RPM. Any ideas? Thanks

-Make sure your fluid is at the right level
-Search "TV Cable Adjustment"/"Kickdown Cable" (TV=Throttle Valve)
-Have you changed tire size or gears
-Search- "seeking gears" or something like that
-Change fluid/filter if it needs it

Just a short list, but a place to start.
Let us know how it's going...

~Good Luck!