Some 2006-2020 Ford F-150 non-Raptor trucks equipped with a TOD (torque on demand) transfer case and 4A selection switch may exhibit a grinding/clicking/ratcheting noise from the front wheel area.

This may be due to partial engagement of the integrated wheel ends (IWE). To correct the condition, locate the vacuum supply line between the source vacuum and the IWE check valve. Remove the vacuum supply line and install vacuum caps at the IWE check valve and the vacuum source. Vacuum cap kits are available as P/N W716372-S300.

Locate the vacuum line from the vacuum source to the check valve.

Cap off the line at the vacuum source and at the IWE check valve.