Replaced 1 cable housing, shifter won't hold??

[BikeTedII]

Hi ALL!
I'm tryng to replace and recalibrate my shifters on my 1999 GT Airstream. It has shifters around the handle bars, pix below. I just replaced one cable housing, ran the cable through. The derailer (this is the front big sprocket derailer) goes back and worth now, but won't hold! Just how does this system work? Does the shifter housing hold the tension? If this is true, than I think I'm out of luck! Or...as I lake a second look, to I simply loosen the housing and park it closer to the handle grip, then this creates the friction?? The out of luck thing comes from the thought that the shifter housing seems to be coming apart, I can see white inside. Pix below! Many thanks, Ted

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[Jordan300]

The shifter itself is what creates the tension. Those grip shifters have been very difficult for me to work on. I had one that went out on me and I was lucky enough to replace it for $7 at my LBS.

[DaveM]

I think the shifter is not all the way together. It is what holds tension on the cable, but it's not just friction between the parts of the shifter. There is usually some small plastic ratchet mechanism inside. You probably need to pull the shifter apart again and see if you can get it back together right.