I bought one of their first inner idler kit for my M7. I got the sled in last week to check it over and found the wheels had come apart. I emailed BDX and they replyed promptly and asked me to call. I called and explained my problem and they informed me they made a mistake for the early M sleds as they had a different mounting position in the rails than the later rail series. They told me they took a different wheel (smaller) and sent me replacements in only 2 days. Pretty good service to me. I don't know but maybe that is what caused the broken shafts also? I also have their tunnel kit and when people where having cracking issues they sent out an update kit (gusset) to prevent this from happening. Again, pretty good service to me. I would recommend their products to anyone, as they've always backed up their products. Just my .02.