I must remove the steering wheel on my model 934005 Ariens tractor to get at the electricals under the dash...but I can't get it off. A parts diagram shows a pin holding it on, which I've removed, and a bolt in the hub of the wheel which I don't seem to have. Looking down through the hole at the center of the wheel, all I see is what appears to be the flat top of a shaft. I've soaked it in pen. oil but it doesn't budge. Any help would be appreciated.