I noticed my vacuum line to my front left hub was missing yesterday. Ford wouldn't honor it on warranty. Said it was consequental damages. Truck has 44,000 miles. I bought a new vacuum harness and replaced the whole thing today. 4 wheel works now, but now I have to travel in reverse to disengage. Never had to do this before and the manual says to shift back to 2H from 4H to just proceed in a foward motion and it will disengage. The dash display says it is in 2H after I turn the switch, but front wheels still have power to them even after 100 yards forward until I travel in reverse. Anyone ever had this problem and if so, how did you fix it?