I personally avoid using the fork altogether but if you end up buying one, make sure that it's of high quality. What I mean by this is that, there are cheap forks that splinter at the point of impact when using a conventional hardened steel hammer or if the end mushrooms on you, that means the steel is of poor quality and the fork shaft actually bends absorbing much of the impact. A Brass Hammer may be a better choice to avoid splintering and mushrooming.
I've been most successful by using a Puller when possible; leave the nut from whatever you're separating partially threaded on to help prevent things from flying should it suddenly break free. I've also been able to strike the opposite sides of what I'm trying to free by using two hammers; you just have to time it so they impact at the same time, see photo. The last methods is to use heat. The problem very often is the potential damage caused to seals and boots; if that doesn't matter, then no problem. For those cases that are sensitive, I purchased a tiny Butane Torch that you can pick up at Radio Shack, Electronic Parts Suppliers, Harbor Freight, etc. They emit a tiny blast torch type of flame that is concentrated in a very small area and still able to produce enough heat to be effective.
I've attached a few photos of pullers that work well, most if not all, are available from Harbor Freight, AutoZone, O'Reilly's, Sears, On-line, etc.
All the best.
Ray
