Might be the clips have fallen off or broken:
- http://www.marlincrawler.com/clutch/release-pilot/clutch-collar-retaining-clips

[Linked Image]

About 11 years ago in Moab, that happened to one guy and he was able to R&R on the trail, just slid the tranny/t-case back a few inches. We even fashioned a new clip out of a stainless steel band clamp, I think he had one clip on there and the other one was missing.