The reverse lock out kit wont help at all if your case is already cracked. I have welded many cases, transmission, reduction gear, transfer, Of those I have only one that didn't eventualy crack again. I cant say that I have ever seen just a case for sale, On cast nodular steel ,I clean , pre heat, and weld with 7808 rod, , continue to apply heat as it cools gentily, on aluminum I have used filler rod, Contamination is the scurge in AL, clean well and use inert backing gas during welding. A very good welder can weld it in place upside down (bottom crack) , unit must be drained and degreased, worth a try, if the alternative is removal anyway, best way to get a good weld is to strip it and weld from both sides, inside and out.Have had reasonable luck doing that on cast and AL . I know they run 12 to 1800 $ to replace, by the time you have it out and disassembled , may as well change it