I've made those spanner nut tools from pieces of square key stock welded to a piece of pipe for many years. A professional parts store like NAPA will have the correct socket, but untold thousands of those nuts have been removed and installed with hammers and punches since those trucks were new. Be careful with the washer that's sandwiched between the nuts with locking tabs that secure both nuts by bending them down- - - -if you take it easy straightening the tabs so the nuts will turn, they're usually reusable.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!