4x4 Problem not engaging
 

i have got this 2004 Ford F150 4x4 Fx4...I have been experiencing this problem while trying to engage the 4 wheel drive...when i put it in 4 wheel drive,,the light comes on..when i give it gas,,i can hear a Slipping grinding noise and the 4x4 aint working...when i put it in Neutral and then turn on the 4x4 and reverse a bit..the 4x4 will engage and work good...what can be going on with...can someone help..

almost sounds like the front actuator isnt moving far enough. The vacuum crap on the front diff. Or see if the shaft moves freely that sticks out of the front diff. Mine was frozen in place, but everything else worked as designed. Lay underneath the front (while in park,e-brake on) have a helper put it in 4x and see how far the actuator actually moves if at all.Just a start.

The 04 up does not work the same way as previous years. It has hubs (IWEs) rather than a center disconnect at the diff.

Problem could be multiple things. If you have ESOF, it could be a problem with the transfer case shift motor, or it could be problems with the IWE's or the vacuum solenoid that controls them.

Is your 4x4 a Heritage or a new body style? Shift lever or switch activated 4x4? And finally are you haveing trouble in 4Hi, 4Lo or both. Regardless you should be able to engage 4Hi while driving forward and 4Lo without having to back up.

JMC, fyi, The 04 Heritage did not come in an FX4. That heritage had very limited models. The only FX4 you could get was the new model.

sorry guys....its the New Body Style step side...its the switch activated...I am having trouble in both 4hi and 4lo...if i dont drive backwards first...i will hear like gears or something slipping...or something not engaging all the way..

By gears slipping do you mean grinding? By design the default position for the IWE (Independent Wheel Ends) is engaged. There is a spring that pushes against the lock up collar to keep it engaged. vacuum is applied to a diaphragm to pull the collar back to disengage. If ever there is a vacuum leak you will have locked hubs and 4x4 will work. In theory this is a great idea. What has happened in the past is that water intrusion in the system caused only partial disengagement and grinding sounds were being heard. A defect or problem in your IWEs or its actuation system may be the cause of the grinding noise. First things first. Can you jack up the front of the truck and support it so the front wheels do not touch the ground? If yes the do it and engage 4Hi. Key on switch to 4Hi. Then get under the truck and try to turn the front driveshaft. It should not turn because it is engaged in the t-case and the front and rear driveshafts are connected. The rear wheels cannot turn because they are on the ground. If it does turn the problem is in the t-case.

Regards

Jean Marc Chartier

Regards