You are going to need the pitman arm puller for this job, no other way around it. Take the big nut off first, then install the puller. Be sure to center it on the pitman arm, and also to grease the center point and the threads on the puller before starting. Put plenty off torque on the puller and when you think you have tight, smack the end of the pullers threaded rod with a hammer. If it doesn't pop off, tighten some more and give it another smack. It helps to hold one hammer on the tool and hit it with a second hammer. You are working with a tapered, splined shaft. The shaft also has one double spline so the arm will only fit one way, it may fit four ways, but only one is correct and it will be pretty clear to you.
Most of the time they will pop off after a few hits, some take heat, and some take really big hammers!
Hope yours is the first kind,
Joe
