We just had the same problem, except it wasn't only a crack, it tore the whole differential casing apart! It's a 2004 L2800. The dealer sold us the tractor with the backhoe (and other attachments) without telling us that we needed any extra supports and now that this just happened last weekend without any forewarning, the dealer just says, "Yep, I've heard of it happening, and we can fix it, but Kubota won't reimburse it. In fact, it might happen again." It would have been nice if the dealer at least recommended the extra parts we needed... we just assumed that they knew what they were selling us.