WHY DOES MODEL MAV 3905 AWW WASHERMAKE SOME MUCH NOISE IS IT THE TRANSMISSION IS IT WORTH IT TO REPAIR IT OR GET A NEW ONE . I BOUGHT IT 2006 AND EXTENDED WARRANTY 4 . JUST EXPIRED MARCH 2011

What is the problem?
Water level is automatically controlled based on what you set it to low, med, or high.

You need to call the manufacturer on this.

Some model have fuse in top control panel, check lid switch, yes large button is the brains, it sometime can fail but usally only takes out 1 of the cycles.

the noise is more than likely coming from the clutch as you correctly surmised that the transmission only functions the paddles. As far as the airplane sound during the spin cycle well that is a bearing issue also called the "spinner support". I would be very careful attempting to replace this part yourself as doing it wrong results in a very leaky washer. The clutch runs about $150 while the spinner support runs about $250 so even though the diagnosis of the tech was clearly wrong (transmissions are relatively cheap and are fairly easy to put into these machine) it still might not be worth the money. Maytag did extend warranties on clutches for very specific models but it only covered the part and not the labor so you may still wind up with an expensive bill. I hope this helped.

The washer was made from 2000 to 2001

That sounds more like the clutch assembly. The clutch may be worn. As the clutch wears out, it may prevent the unit from spinning well or at all. If the clutch is worn, you need to replace it.

gringing noise is never a good sign check the main bearing these are notorious for having bearings go and if it is bearing find a new machine its not worth fixing it is costs more then the machine is worth to replace

There's this website www.reliable-store.com
They have books on ALL vehicles.
it covers wiring diagrams, electrical diagrams,
fuse diagram, torque specs, PCV, error codes, fault codes, service info, repair info, parts info, troubleshooting owner's/service/repair/parts/maintenance manuals etc everything totally..
I have 1987 toyota 4runner model and I
keep servicing and when needed repair it on my own. worth it !!!

this is my experience repairing the maytag washer Atlantis mav series 9750 aww, I had to replace the spin bearing since it was making a jet engine noise when it was spinning out the water. its not an easy job for my 1st time taking this machine apart, you literally take it all apart to get to this bearing, but now I can show how to do it with pictures making it easier for you to do it. even if you have to replace something other than the spin bearing, this how to tutorial will show you how to get to most of the parts in this machine, parts are not that expensive, 50-80for bearing kit, here is my site on how to do it
there is also a download for the repair manual
http://maytagwasherrepair.googlepages.com/index.html

this is my experience repairing the maytag washer Atlantis mav series 9750 aww, I had to replace the spin bearing since it was making a jet engine noise when it was spinning out the water. its not an easy job for my 1st time taking this machine apart, you literally take it all apart to get to this bearing, but now I can show how to do it with pictures making it easier for you to do it. even if you have to replace something other than the spin bearing, this how to tutorial will show you how to get to most of the parts in this machine
tutorial located here tutorial located here https://sites.google.com/site/maytagwasherrepair/maytag-washer-repair