yet another reason i avoid things branded as SRAM...

there seems to be a red plastic part that clips over the axle end, as Dan asked about... if it's missing, it probably broke and must be replaced.
contact a SRAM dealer with any info you can find on your hub.. there are a couple differing models with the same basic name.
good luck.

i've worked on dozens of other enclosed gear hubs/shifters... they use a simple bell crank design at the axle, or the classic rod and tiny chain, ala sturmey archer.... apparently, SRAM felt some need to re-engineer the wheel... again.