Differential housing corrosion

Found a leak in upper rear diff housing. Corrected by cleaning with wire brush on grinder and subsequently mig welding a patch and the covering with bedliner spray. Only wish no internal damage due to low diffenrential oil level will happen. Just wrote to Toyota Canada but no grat expectations.
Very deceived to read that such problem existed on first gen Tundras and Toyota did not correct it. This is my 9 th Toyota product and never seen such a bad corrosion issue.
Perforation on body parts is normal but on a diffential housing, come on !
Not sure my next pick up will be a Toyota.

 

Post some photos of you can.

 

If toyota won't fix it; I'm sure ford, dodge, and chevy would.

 

The rear axle housing is made up of several different pieces of steel. The part that makes up the "tubes" that go the wheels is thick metal. The front of the center has to be open to mount the third member to. The rear is just thin steel. It rusted out on my 2000 Tundra. I ended up draining the fluid and cutting all of that thin piece of steel off and made a new dished shape piece for it. If it's steel it's going to rust. I don't care which brand made it.