There is a very heavy duty puller called- - - -wait for it- - - -a "Pitman Arm Puller"! The splined, tapered shaft on the steering gear, and the corresponding splined taper on the arm form a very tight fit. I usually use a 3/4" drive impact wrench on the puller. A lot of them actually have a couple of bolts that keep the puller jaws from spreading out and slipping off. Some auto parts stores will rent that type of tool, with a big security deposit.
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!