I search an transition effect...

In FCP7 there was a transition that push the first clip to the left (or right, top, bottom ect.) to the next clip.

Is there some same effect for FCPX?

Yes, there is. It's a little hidden though. Not in front of my machine, but if I remember rightly it's in the Wipe transition. There is a popup that keys you select the behavior and I believe one option is push. Onscreen controls adjust the push direction. Doing this all from memory from a couple of months ago, so you might need to do a little poking around, but it is there.

Pretty close Tom, it's in the Movements>Slides. I'm still finding myself hunting
for transitions etc that I know are there but can't remember what they've be renamed
as!

I found the Wipe transition, but what happens here is that the next clip rolls over the first clip.
What I want is that the next clip push the first clip.

Example:

Select Transitions then go to Movements>Slides

Wow great! I saw your first comment but I don't look good.
Thanks!