Why is my Ford F150 not engaging 4 wheel?
Why is my Ford F150 not engaging 4 wheel? Operationally vacuum holds the IWE ( Integrated Wheel Ends ) out, and once vac is removed the spring engages the IWE. Key on, engage 4x4 and try to turn the front drive shaft. If it turns it is a problem with the transfer case. If it doesn't it is a front axle engagement problem. When did Ford F150 have weak leaf springs? Weak leaf springs along the front of the vehicle were found in the 1991-94 Ford F150 models. New springs or added leaves will fix the issue, but some trucks...