When i select a piece and delete history it’s not animating anymore in my scene, how come?
(i tried deleting history on it because UVs kept moving when animating)

To respond to both of your posts, it sounds like you still have an active UV projection or Transfer UV node. If you have the model skinned or rigged in any way that has history, then when you delete history you will delete all of those connections...and therefore cannot animate anymore.
The way to deal with this is to go to the option below Delete History which is Delete Non-Deformer History. You can just use the default option for it.
This will delete things like UV mapping, Extrudes, Splits, Merges...which is usually what you want.
The only problem is if you are animating an extrude or something like that.
If this doesn’t work, tell me a little more about your setup and we can get you up and running soon.
All the best.
~Ben

Thank you very much i’ll try things from that angle to start.

I tried and no differences, i even tried to apply a unique UV to the top part of the crane (which is the only part of my animation that goes wrong) and still, UVs moving all around when i press play. I though about one thing i heard which is baking uv map, i don’t know maybe it’s something even more basic. My real question of course bends to why this mess only occurs to the top part of the head when everything else seems to work properly and i haven’t found where it differs from the rest.

If you want to post a screen shot or your scene file we can try to get to the bottom of this.
In the screen shot is would be good to see the Inputs in the under the Channel Box as well as the viewport.

Baking a UV map has no effect on how something looks or behaves within Maya.
It is something to do if you want to paint a texture in a program like Photoshop.
It may be helpful in this case just to see your UV layout...but it won’t fix your problem.
To do it, open the UV texture editor and go to POLYGONS - UV snapshot (the last item)
A good UV image is at least 1024 x 1024 and a TIFF image (whatever format you like).
Unless you are doing some crazy specialized UVing, the rest of the settings should be fine.

Anyway, I am happy to keep working this out if you feel like posting more.
~Ben

Well i was just a step away from the solution and i admit i’ve been a little quick on the forum trigger, solution lied in the texture editor indeed, the part that gave me headaches wasn’t over the texture, somehow i placed it over like all the other pieces and bam, what’s next. Thnk you very much anyway, been a pleasure. Like most of the time, simple does it. eeehaaaa!