I discovered why the splines on the passenger side front axle (2004 E500 4matic) won't go all the way into the transfer case. There is a smooth round 1/2" pin (?) at the far end of the splines ithat's blocking the axle spline from going all the way in. What happened? Did something break internally? Is there a way to recess the pin to allow full entrance into the transfer case? Thank you.