Never heard this was possible on the highway. While I was out of state there were some bad rain storms with wind. The wife was driving my truck, she got home and said the whole wheel was smoking. Pretty much everything that used to be my Yukon locking hub is now a pile of shavings. !/2 the spring in it is missing, snap ring for the axle shaft was popped off and was floating around in there. The 2 "locking cog" pieces are ground down. Had to pry it off of the axle shaft and eventually it jammed. I had to use a very small gear puller to remove it. Looks like the spindle nut backed off a bit. The little pin on that locking washer is gone. I ordered all the bearings and seals- but now looks like I need to order a new spindle also. The spindle nut threads are hashed. Part of what I ordered was a "x lock" locking spindle nut. Everyone ever use one? This truck has always had a history of the spindle nuts getting a bit loose. But now that I've bought them some say they are incompatible with the Yukon hubs. No reason was given on why it would cause issues. On to the next issue- those hubs are expensive. I'm not sure if they sell replacement pieces. And if they did- then I'd be mad if these 2 parts don't work together. In the meantime I checked my garage and I do still have the original parts from when it was a full time 4. The little chrome caps and the "slug?" that permanently locks the hub. Maybe this is the safe route to go? With no moving parts and the spindle nut locked down I shouldn't ever have issues (hahahahaa!). The truck is pretty much only for off road and forest service roads up to lookouts, camping spots, and lakes. Maximum highway distance is usually no more than 60 miles and I typically only do 60 mph.