Maybe just alittle bit will, but if you concerned about it, either lift the rear up a little bit, or park with the nose low. By the way, you don't need to lift the rear alot, I like to back up on top of like a block of 4x4 or maybe put the nose down in a shallow hole. As for actually gresing the slip yoke, the normal movements from driving keep the splines lubed with ATF inside the x-case anyway. If you are greasing the FRONT shaft, then all you may need to do is jack up one tire so that you can rotate the shaft and make sure to grease the joints while you are at it.