akakeester

So I searched the forum pretty extensively and havent yet come across an exact version of the issue I have with my FX4. I can engage 4H without issue when at rest, but if Im moving, the light only comes on and you can hear some whirring type noise, but 4WD wont engage. When I come to a rest again, the 4H engages easily. I noticed this sometime after I had put a 2" leveling kit on the front coil towers. Easy answer is to take off the leveling kit, but Im not entirely sure that is what causes this. Anyone have suggestions?

Montano

From what I understand, the truck must be in Neutral with your foot on the brake in order to engage 4 low. That's how I do it and I have not had any issues.

mattd17

well, to me it sounds almost as if your IWE's are not engaging against the moving hub.... i would try to blow out the hub vent lines with some compressed air, and see if that allows it to engage better.

akakeester

Thanks for the replys guys. After more research on the forum and the past threads, I chose to replace the IWE Solenoid in the engine compartment and attempt to evacuate any other moisture that may be in the lines. After only a short bit of time on the truck and $27 later for the part, everything is in tip top shape again and the 4WD is engaging on the fly properly.

For any of you that may come across the same issues with intermittent or poor shift on the fly 4H, check out the thread link for great info and pics: https://www.f150forum.com/showthread...rvice+bulletin

The part number is called the IWE Solenoid and the Ford OEM part # is 6L3Z-9E441-A and is between $27 - $36 depending on your dealership. I dont believe you will find this part at the local Autozone/Oreilly's etc. On a side note, the parts guy at the dealership stated that they replace these things all the time.