my 12l4 hub just broke, the smaller side of the aluminum cracked and fell off, it looked a little weak to start, i put crc hubs on my slapamster ms 2.2 and they seem a lot stronger, albeit heavier. i also have the slapmaster thrust bearing kit, that thing is worth its weight in gold, a must have to keep bearings and diffs smooth in the rear. i use regular diff balls and after 2 weeks of racing, probably 12 heats, the diff is still super smooth. i also use all 12 balls in the spur gear, although i did not notice a difference in smoothness from just using 6 or 8 depending on spur gear.