midrange

I'm pretty sure my IWE's are bad on my '08 SuperCrew. But I want to confirm my findings first.

When driving the truck and 4x4 was selected, I had a grinding sound that seemed to come from the left front wheel. I couldn't tell if there was any noise from the right. The noise stopped when I switched off the 4x4.

If I understand the system correctly, when there is no vacuum on the system (meaning 4x4 is switched on), the IWE's should couple with the cv shafts, and the shafts should rotate when I spin the wheels.

If that is the case, with the truck off, and the front end in the air, I can rotate both the left and right front wheels and neither cv shaft will rotate.

When I apply vacuum to the lines before and after the vacuum solenoid, the vacuum holds, (indicates that there are no leaks in the lines or IWE's), there is still no movement of the cv shafts when the wheels are rotated. Which also indicates that the IWE's are not coupled with the shafts.

I'm thinking that due to the previous owner almost never needing 4 wheel drive, that the IWE's are stuck open.
Is there a chance I can loosen them up, or should I just change them out?

I only drove 3-4 blocks when I heard the grinding and quickly shut off the 4x4, so could the IWE be chewed up?

jamie930

You could have a bad IWE solenoid up on the firewall
When mine went bad it would not release the vacuum to lock the hubs.

Sounds like that is what yours is doing. When the vacuum starts to leak down you get the partial engagement( the grinding noise).

Pull the vacuum line off the solenoid and try your 4wd again and see if the noise is gone

4x4 Issues

• Troubleshooting Guide: https://www.f150forum.com/f4/4x4-trou...g-guide-39789/
• IWE Solenoid: https://www.f150forum.com/f4/iwe-sole...nfo-all-46807/
• Changing the IWE Solenoid: https://www.f150forum.com/f4/my-satur...ge-04-a-18608/

midrange

I took the lines off right at the IWE's and they still didn't engage the cv shafts.
I really don't want a project right now, but it's no fun taking off from a stop in the snow with traffic behind me. LOL I may have to find the time and just 'git-r dun'.....

lewissa81

If your iwe's aren't engaging(spinning the cv shaft) when there is NO vacuum, then the actuators are bad. There's no need for further testing and you can't loosen them. You'll have to take it all apart to see if the hubs are good or bad.

midrange

That's what I figured, but wanted to double check to be sure.
Well, looks like I have a date with my truck on the lift this weekend.