Mine has the geared tab washers and seems fine, but now you've got me worried. Has anyone had these fail? Reusing the washers asks for trouble, but as long as they engage well, as an engineer I still feel safe enough. It's all managed risk at 60mph with 3 tons...
The locking nuts are an interesting idea.
BDGR
Yes, there have been failures, whether it is "often" or not I'll leave for you to decide. IMO, it's the most unsafe thing of the HMMWV/H1 design. Two members on the Hummer Network had wheels fly off at interstate speeds this year. It's not exactly a large crowd of owners.
Engineering wise, consider that you have a small metal tab that is holding that entire wheel if the spindle nut starts to lose torque. That small metal tab is not always engaged perfectly into the openings on the spindle nut, either. While sometimes the tab shears off, there are also times where the poor engagement lets the spindle nut twist and push the little washer tab out and then chew through it over time.
In my opinion, the only downside to the BlueHummer kit is the price. Let your mind think about this happening to you on the highway. A 160 lb wheel/tire combo rolling at 60 mph has a LOT of potential energy and absolutely has the potential to be deadly, not to mention the risk of roll-over and worse in your truck. Remember that those lightweight aluminum A, B, and C pillars are NOT roll-over protection. They will fold. And that is exactly the kind of incident the safety Nazis of this country and in your state would want to rip these trucks off of the road. I wouldn't go so far as to call this a design flaw, but it requires perfect execution of installation of the spindle nut and lock washers to be good at its job, and it’s even possible that’s not enough. DO NOT TAKE SHORTCUTS.
I encourage anyone who owns a HMMWV to also join the Hummer Network forums and listen and learn. While there is vast experience on this website with military vehicles, the guys with the H1s have been abusing, working on, and buying and selling these vehicles longer than almost all of us have even had the chance of owning a military one.
http://www.hummernetworkforums.com/viewtopic.php?t=244966&postdays=0&postorder=asc&start=0