When I drive my 2006 F-150 Super Crew 5.4 i get very random episodes of what I believe to be partial engagement of the 4 wheel drive which sounds like I am dragging a shopping cart under my truck and there is the friction of the lower gear. I usually pull to the side and it stops. This has happended 4 times since I have owned the truck. I asked some people and they said I may have a leak in a vacuum hose that keeps the drive from engaging. Any help or suggestions would be appreciated. Truck is out of warranty.

 

Yes you could have a vacuum leak, water in your vacuum lines, or a bad IWE solenoid. The IWE is a common failure on these trucks. I would try and fix this soon since you could do damage to your hubs.

 

Thanks for the info I will replace the IWE solenoid and check vacuum lines.