I agree with the blue locktite as mentioned above.

 

It may be easier to disconnect the cable at the wheel and pull the inner out and just try to rethread the outer back into place. Once the outer is screwed in tight then feed the inner back in and reconnect the cable at the wheel.

 

Same thing happened to me, was easily fixed with blue threadlocker (permatex) same as Loctite I am sure.

 

yeah I got that bitch back on with the offbrand locktite, now we shall see if it holds up