Got a fairly new transfer case. Here's the deal:

I have an automatic transmission...When I shift IN or OUT of 4L while moving (in N or drive) faster than 5 miles per hr. I hear the gears grind! <img src="/forums/images/graemlins/confused.gif" alt="" />

I have to come to almost a complete stop before I can shift and only then it engages without incident.

What could be wrong?