On my 66 Newport, I have installed a newly rebuilt 745 transmission. I cleaned and lubed the yoke splines with some grease. I am meeting a lot of resistance trying to get the yoke to slide over the splines. The splines are engaged. I bumped up against what I think is the rear oil seal, and had to gently persuade it past that with a block and hammer. So far nothing is binding though; I can still slide the yoke back again by hand. I am still not in far enough, and the yoke does not want to go further. I am afraid to get too aggressive. Any ideas what is going on?