I decided to change the oil in my NP205 and found a couple of loose bolts to the Getrag. I filled the oil to the proper level and tighened the bolts, (are there any to tighten from the inside?) and took a test drive. Suddenly the transfer case won't stay in gear. Every time I let off the throttle in 2WH, it pops into neutral. What keeps the thing in gear? Is there a detent on the rod, is it in the linkage? I guess I should have left the old oil in there. ANy inpit on this would be greatly appreciated. Thanks.