If the hex tube is rusted out, you might want to check your cable over very carefully, too. Look especially at the joint where it connects to the t-bar.
I hadn't given mine much thought either until a couple of weeks ago, while on my way to work at night, I was crossing some rough R. R. tracks and found someone else's spare tire/rim with the t-bar and @ 1/4" of their cable still rusted and stuck in the hub hole... Nothing I can use; a Chevy 5-lug. Tire still looks new, though. Won't they be surprised when they have a flat tire and go to remove their spare...
I'm going to do something different than the hex tube. I'm not even sure i have the tool that fits it. It is also in the way of the Line of Fire l. e. d. light bar I recently purchased and want to install. And I'm going to make some kind of shield for the wheel. Mine is disgustingly rusty from taking all of the gravel road and salt spray over all these years.