The first samurai 4:1 tcase gears were actually welded gears. They took gears from the samurai tcase and the sj410 tcase, cut some of them and mixed and matched and welded them back together. There are probably 1000s of these welded gears in use. I have read that several people had problems with the gears breaking at the welds, but they just rewelded them and they have held up fine ever since....kinda odd, you would think that the vendors/shops/companys that were welding the gears originally could do a better job welding than the end user...but I guess not.