Recently my transfer case was rebuilt along with a new clutch installed. After the transfer case was rebuilt, the 4x4 actuator started attempting to engage randomly driving down the road. I've replaced the actuator in hopes of eliminating the problem with no luck, vacuum lines seem to in good condition. The vacuum line is currently disconnected to avoid damage. Any idea's what causes the the actuator to engage randomly?

 

Sticking transfer case switch that controls the vacuum

 

You have two vac lines running to the CAD, One engages it and the other disengages it. It is either sticking or not working.

 

When the line is disconnected, it still attempts to engage? Originally I removed the front drive line and the symptom went away. I reinstalled the drive line once i replaced the actuator recently but disconnected the vacuum line from the actuator still resulting in the random engagement. Perhaps the transfer case is attempting to engage rather than the actuator?

 

With the vacuum lines disconnected I don't see a way it could try to engage. The transfer case could be, maybe your linkage needs adjusting