I'm installing Koni Reds on my 87 Quad (front end first) and am having A TIME pushing the bottom of the shock with the slide-on bushing back on the post (shaft). I know they were kinda tough to remove, but I simply cannot get the new ones to slide back on. I cleaned off the post, even put a little 3-in-1 on for some lube, but I cannot get it completely back on. It goes only so far and then stops. I checked the part # on the Koni site and they're correct (80 1551). Bought them from IAP. I expected some resistance, because they were tough to remove, but this seems excessive. Any advice??