2005 X5 4.4 right front axle install problem

[pghguy517]

Hi, In the middle of replacing the alternator bracket seal, but ran into a problem when reinserting the right front axle into the differential.
I can engage the first part of the axle splines up to what I believe is the spring clip, but can't get past this point. I've tried pushing and tapping to get past the spring clip, but it won't go in. I've hit it much harder than a tap a bunch of times, but no luck. I'm worried that something will break, especially since the differential is mounted to the side of the cast aluminum oil pan.
Also, when removing the axle front differential, I had to hit it hard to remove. But I've hit it even harder to install, and no luck.
Any suggestions? Thanks