I found an old motorcycle spark plug wrench with a 19MM base, and a square throat (inside) that I was able to jury rig with a short extension to be able to use my torque wrench to torque the front axle to spec. You probably have one lying around somewhere too - the price is right!
McMaster Carr or McMaster Carr has a 19mm 1/2 inch drive allan head socket for like 12.00 or something extremly low like that...I bought one and I had it the next day, Snap-On wanted like 40 bucks for one...
I did find the item number it is 5571A79. Just used it the other night it is always great to have the right tool for the job.
I got cheap ($9) and went to SEARS and found a cold chisel with a 19mm handle, cut half of it off with cut off wheel, dressed it down a little and Waa! Laa! instant Yamaha axle tool and a short chisel to boot! lol Seriously though it works great and if you needed it yesterday, SEARS is the place!