A word to the wise on the TJ shafts, if you currently have a YJ (which I am assuming you do) then upgrading to TJ shafts will mean that your front drive shaft will spin all of the time. The TJ's are designed to spin all the time, but the YJ's were not. You could potentially end up fighting some drivetrain vibes etc.. from the shaft spinning at highway speeds. I am not speaking from personal experience, but I have read of other people having some problems when installing TJ shafts into a YJ. The problems are ones that can be solved, but if all you are looking for is to get your system working again the way it used to, you are probably better off either troubleshooting the Vacuum Motor system, or upgrading to the cable type.