OK, here's mine: myself and a mechanic friend went through my system today. He tested the passenger actuator and it seems to work fine. Tested the drivers side and it is seized, so I need to replace the vacuum hub assembly. When driving, there is a whining that kicks in after a while. It's not there all the time so it can only be the 'working' passenger side engaging intermittently. He tested the vacuum lines for leaks. We came to the two lines coming from behind the engine and the one going to the 4x4 system appeared to have a very weak vacuum. The line going to the solenoid on the fuel rail(don't know what this is) was much stronger in vacuum. We switched the lines for now to keep the passenger side from locking in(hopefully). Any insight into this is appreciated and I'd like to know what the vacuum line going to the solenoid on the fuel rail is.