Having done this repair in the last few weeks...make sure it's level and have a helper push it in or tap it home.
I found having a friends help was invaluable.

I bet you're questioning how can it not be level when you have the splines engaged?! Trust me...it's not level if you can't get the clip to engage! Just have to play with it.

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2002 4.4 Sport
134k miles and counting