I have a 1998 XJ Limited 4.0 Auto... When I come to a complete stop, or after shifting into drive after backing out of a parking space, it drops from first to neutral then pops back into first after a few seconds. It feels like some sort of a engage/disengage problem, like the teeth of something are pulling away and then catching again. When it pops back into first and I happen to be giving it gas, it will buck. If I just wait with my foot on the brake, it calmly goes back into gear and I'm on my way... Otherwise, its shifting and everything else is normal. I flushed the transmission and I could feel an improvement in the overall feeling, but it didn't cure the slipping out of first gear thing from a stop...

Any thoughts?

Thanks!!