Read all posts re. unclogging vacuum hoses and lines to hubs. At dealership now, abnd verdict for my intermittent 4WD failure is clogged solenoid. They are replacing the part. My husband wants a permanent, quick, reliable fix - is it possible to install manually locking hubs? What is involved in bypassing the vacuum system? Does anything have to be closed off or removed to prevent issues with, e.g., the vacuum system for the heater controls? Don't know if the two system are connected in any way. Any ideas are welcomed. What are the preferred manual hub parts? Molly in Colorado