Rear wiper assembly rusted I've been trying to get this off since late winter, spraying with PBB, tapping, prying. The cast aluminum arm was locked onto the tapered, splined drive post. I finally covered the surrounding hatch with aluminum foil and very carefully heated it with my mapp-gas torch. It popped off first try after that. My wife's Dad had a large body and repair shop, has done hundreds of these, said he often had to split them to get them off. Now I need a new wiper arm, Dan?