Drive shaft replacement-Kubota G1800

I've just finished installing the drive shaft from the engine to the hydrostatic transmission on my diesel G1800. I removed the radiator to make it easier to attach the engine side shaft yoke. I removed the splined plate held on by three bolts and slid the shaft yoke on to it. Then reattached the three holed plate. It went on but it was a very tight fit. Being that the shaft has splined yokes on both ends, I would assume the shaft would have some minor movement to allow for flex between the engine and transmission while the lawn tractor is in motion. Did any of you who have replaced this particular shaft have to force it in also or did yours go in easily. I'm a bit worried about starting it in case it should have slid in smoothly. By the way, I did loosen the set screw on the transmission splined shaft collar and pushed it as far back toward the transmission as it would go to get all the room I could.