I have a brand new maytag 4000 series front loader washer that shakes across the floor while on spin cycle. it is level and balanced. not sure what is goin on.

Replace all four struts

Did you set the back feet before leveling? On most units to set and lock the back feet you need to pull the top towards you so that the back is raised off the floor, then set it down again, this will release the feet and lock then down. The you level the two front feet. After this is done you must make sure your load is balanced. Distribute the items as evenly as you can in the tub. Once it gets to the spin cycle if its walking or shaking a lot, stop it and redistribute the items more evenly in the tub. Also try not to overload the unit or combining many heavy items with few light ones. If this is a new machine, did you remove the shipping locks from the back before using it? They have plastic strips attached to them, make sure they have all been removed, as well as any shipping bolts.

the machine is not level... put a level across front back sides to check adjust legs leveling bolts as needed.... also is the machine installed on a carpet floor??? if yes put a sheet of plywood under machine so it wont "bounce" on floor.

All front loaders shake to some extent. It depends on the balance of the load. It is especially evident in the spin cycle due to the high speeds. Also these machines are best placed on a solid cement floor. They can shake an entire house if on the first or second floor and the floors are not well reinforced.

The shock absorbers that hold the tank are broken. Then the load will move the washer all over the place.
Look online for an exploded diagram and order the new shocks for it

IT SOUNDS LIKE THE PAKING STRAPS MIGHT NOT HAVE BEEN FULLY REMOVED, OR THE HAS BEEN A SMALL CLOTHING ITEM THAT SLIPPED THRU THE OPENING WHEN YOU OPEN THE DOOR THERE IS A SEAL AND IT IS VARY FLEXABLE SOMETHING COULD HAVE GOT THRU, BUT IT STILL SOUNDS LIKE THE PACKING STRAP WAS NOT REMOVED ALL THE WAY IT COULD HAVE BROKE OFF WHEN BEING PULLED OUT, IT'S JUST A PLASTIC STRAP BUT MIGHT HAVE TO REMOVE THE FRONT COVER TO GET TO IT,

It might not be the leveling of it. Front load washing machines have a lot of power when they go into their spin cycle. Depending on your floor and if the washer is upstairs it is going to shake and make a ton of noise. When I worked for Sears as a tech I had to explain this to a lot of people that just got their first front loaders. Some of them would say that it sounded like a plane was flying threw the house when it would spin. Others said it was like an earthquake. Front loaders don't work good in mobile homes either. Not saying that you have one. Anyway, when these go into spin the have so much force coming from them and all that force goes straight to the floor. If your floor is weak or that washer is in a spot where it is weak it's going to shake. The best thing to do is go under the house and put in a support beam right under the washer. This will get it to lighten up a bit and maybe even fix all together. Give that a try and see how that does. Let me know if you have any other questions and let me know if this was helpful for you. Good luck.

THERE ARE SHOCK ABSORBERS IN THIS UNIT,SOUNDS LIKE ONE OF THEM IS BROKEN.HOPE THIS HELPS

make sure the transport tie downs have been removed during installation and that all four feet are adjusted properly so machine does not rock.Also make sure your floor is reasonably solid.

Try placing it on a rubber mat or carpet that has a rubber backing. The floor may be too smooth and allows it to walk.