4x4 slips shiftin gears starting and stopping

After taking my 2000 G C Jeep out of storage, I drained the fluid and changed the filters put it back together and it does not move when put in gear, only if you race the engine at a high RPM then it jerks in gear for a min. could this be a bad elect. conection or sticky valve ?????? got any help out there.

You might already know but when shifting into 4wd you can shift into 4hi while driving as long as the tires,(all four) are travelling the same speed. you can't shift into 4wd if you are spinning. 4 low you have to completely stop. When you are in 4 low as you know the power of vehicle is greatly increased due to gear reduction. so if you are seeing slipping symptoms, you might want to change transmission filter. It might not be much help to you but it might prevent problems down the road. also when changing fluid be sure to put mopar transmission fluid for replacement on jeep. like gm calls for dexron. the transfer case on dodge and jeeps also takes transmission fluid. I had to replace a t-case on my friends dakota that was making a grinding noise and it turns out a seal had leaked some fluid out and burnt up some bearings. pretty expensive. they are chain driven. hope I didnt get too carried away, because I am not a transmission expert but I just wanted to share what I did know with you.