When regular bears just aren't cutting it anymore, try giant murderous cyborg bears!
15 magical beast RHD aren't great as far as a chassis goes, though being Large with 33 strength makes up for that to some extent. The ability scores other than strength range from pretty good (20 constitution) to awful (2 intelligence).
40 ft. land speed is nothing special at this level (Boots of Speed are incredibly useful and only 12000 GP). Two 2d6 claws and a 4d6 bite are reasonably nice, though mauler PCs will probably sacrifice the latter for a weapon. +7 natural armor is okay.
Special qualities are mostly underwhelming. Light Fortification, Trample, and Improved Grab aren't particularly great, and Grafted Armor is just a +5 armor bonus hidden in a paragraph of unnecessary text. Sickening Aura is intriguing, but ultimately not that great (if you really want to be a walking sickness vector, play something better and take Stench of the Dead).
Ultimately, I'm not convinced the ironclad mauler is worth its large amount of RHD. The high strength is basically the only selling point here, and even that is not ridiculously hard to get on a less awful character. -0 LA.