Locknuts are commonly used to attach wheel rims to threaded bolt shafts. The nut "locks" because of a nylon insert that lines the centre hole of the nut, which allows it to grip or lock onto the threads of the shaft. If the nylon insert becomes stripped, then removing the locknut can be difficult. There are three ways to remove a stripped locknut; try the easiest one before going on to the next technique. If all else fails, you will have to cut the locknut off by hand.
Push your locking wheel nut remover socket (or the locknut key socket that came with your car) onto your socket wrench.
Push the socket onto the locknut. Locknut key sockets and locking wheel nut removers have tapered ends that are grooved on the inside; as such, they require a great deal more force to seat on the nut then regular sockets.
Turn the nut clockwise with your socket wrench, tightening it. Often, by moving the nut in the opposite direction (then removing it), you can force the nylon insert back into alignment with the threads.
Turn the nut counter-clockwise with your socket wrench, to loosen it. Remove the nut. If you still cannot remove the stripped locknut, go onto the next section.
Push your locking wheel nut remover socket (or the locknut key socket that came with your car) onto your socket wrench. Set the wrench aside.
Light your hand held butane torch (follow the instructions that came with the torch kit) and hold the torch so that the flame is just touching the locknut. Keep the flame on the nut until you smell the nylon insert beginning to melt. Turn the torch off.
Attach the socket wrench to the locknut and turn the nut counter-clockwise to remove it. The nut should come off; if it does not, go on to the third section.
Use a hacksaw to cut the nut, so that it is split down the side face (not along the diameter of the nut).
Press the edge of a flathead screwdriver into the cut that you just made.
Hammer the handle of the screwdriver to drive the tip into the cut, then split the nut off the bolt.
Keep the locknut key that came with your car in your car's glove compartment, not in your toolbox. This way, there is no chance it may get misplaced while using other tools, and you will always be able to find it.
Always wear safety glasses when breaking off a locknut from a bolt: The bolt can fly up and hit you in the eye, causing serious injury.