I'm attempting to remove the harmonic balancer to replace the front seal in my 1967 250 SL. I have removed everything in front of it and have removed the the big bolt and 3 large washers. I then put a sturdy bolt head into the end of the crank snout, not covering the two dowels. I then applied a 3 prong gear puller and applied pressure, a lot of pressure and the balancer does not budge. I'm afraid something will explode if I apply more torque. There is no indication of rust or other corrosion. I'm reading abiut the 230s having a weakness in this area. I've considered heating the balancer but realize this could destroy the seal and create more problems if I can't get the balancer off..
How do I get this damn balancer off? What am I doing wrong?