99 JGC engine shudder after shifting

I have a 99 grand cherokee LTD 4WD, and lately, when i am accelerating up a hill, as i approach the top of the hill and the car shifts up to the next gear, it shudders. If i take my foot off the accelerator for a few seconds and then put it back on, the car usually runs smoothly. What's happening here? It doesn't seem to be a matter of the engine being cold, and i checked the transmission fluid level, which is fine.

Might be going in and out of lockup. Check your RPM when this happens and see how much they go up. Turn your overdrive off and see if it happens.