How to get housing seated into shifter barrel adjuster I just picked my bike up after getting some work done. Shifting was a little off so I tried to adjust the barrel adjuster on the tiagra SL-4700 shifter and it looks like the housing has come loose :|

When I move the shifter to the lowest position the housing looks ok, but as I shift up the whole housing moves out.

When I tried to get it back in before and shift up / down it pushed the cable end out of the back of the shifter.

It looks like everything else is firm: the housing around the derailleur and the bottom bracket seem solid.

I haven't had this problem before. How can I get the cable back into position properly?

Thanks in advance!
I think that bit of plastic on the end of the housing is called the "ferrule".

If you have a spare and want to replace it you have to get the inner cable out which means cutting the cap off the far end of it (down by the derailleur) and pulling the cable out. Then you put another cap on the far end after replacing the ferrule.

The shifter end of the cable has a lump of metal permanently attached to it so it can't be unthreaded from that end. 

I think it would also probably work fine to just clean it up as best you can and put a couple of drops of superglue between the housing and the ferrule. That way you don't need to take the inner out.