Many posts are here and out there about intermittent grinding noises from 4wd Expeditions and F150’s. Source is usually only partial vacuum getting to the vacuum operated front wheel hubs if you have 4wd.
Ford released a $20 vacuum hose for the front wheel hub (IWE) supply which has an updated blue one way check valve so vacuum stays in the box it attaches to which is a vacuum reservoir. This ensures strong vacuum to the front wheel hubs at all times to keep them disengaged in 2wd.
Poor vacuum results in them finding a partial position and grinding / damage can occur. The white valves were known to leak and not allow the vacuum to stay present at the tank.
For $20 and no tools, the updated vacuum hose can be installed in 5 minutes. Part number is FL3Z-3A788-b
Check under your hood on the drivers side firewall and see if you have the blue valve. Old style is the white valve in some of the photos. It’s a real easy install and worth it!
Ford released a $20 vacuum hose for the front wheel hub (IWE) supply which has an updated blue one way check valve so vacuum stays in the box it attaches to which is a vacuum reservoir. This ensures strong vacuum to the front wheel hubs at all times to keep them disengaged in 2wd.
Poor vacuum results in them finding a partial position and grinding / damage can occur. The white valves were known to leak and not allow the vacuum to stay present at the tank.
For $20 and no tools, the updated vacuum hose can be installed in 5 minutes. Part number is FL3Z-3A788-b
Check under your hood on the drivers side firewall and see if you have the blue valve. Old style is the white valve in some of the photos. It’s a real easy install and worth it!