GEN 2 4WD Issue While in 2WD

[John Doe]

I have a 2017 Gen 2 with about 60k miles.

Whenever I put it in normal 2 wheel drive a strange noise comes up on the driver's left side. It sounds and feels like the 4wd is trying to engage (almost a grinding feeling). It always eventually gets louder and feels like it snaps forward like something slipped and then the noise goes away for a while but always returns in about 30 seconds to a couple of minutes.

This usually always happens at highway cruising speeds. Only in 2WD though. The problem never occurs in 4A.

The problem arose after I took it mudding pretty hard.

I've cleaned all of the mud out and I am still having the issue.

The dealership didn't know what to say so I said screw it ill fix it myself. I would really appreciate any help y'all could give me!!!!!!

 

[smurfslayer]

Your problem description has all the hallmarks of the IWE issue. there’s a vacuum piece right by the master cylinder that is typically the cause, a sub $10 part. I think it’s the “IWE check valve”.

keep it in 4a for now, because if the IWE is trying to engage the hubs it will cause some damage. My understanding is that the system “defaults” to locked hubs, and that the check valve engages to hold 2h. when the valve fails, it tries to lock the hubs but doesn’t have enough vacuum to do it, causing a partial engagement.

If the check valve doesn’t fix it, you may already have damage, but, from your description, running around in 4a is fine, you probably aren’t to the damaged parts yet.

 

[Gatica]

I just had this fixed on my truck. There is a Tsb on it. TSB 20-2013, they should have found it when you took to dealer. Like smurf said keep it on 4auto for now till you have them fix it. If you want to do your self I have all the part #. Good luck

 

[John Doe]

I replaced the IWE check valve and it drives perfect in 2 wheel!!! Thank yall for all of the help. Saved me some money for sure.

By the way, the dealer tried to charge me 42$ for the part which is absurd. I showed him the part online for 15$ and he brought his price down to 21$. DONT LET DEALERSHIPS SCAM YOU!!!!!!

 

[Flash1034]

Please post the part number for said IWE check valve. Sounds like something I might wanna keep in the glovebox as a spare.
Thanks.

 

[BadAss]

I had the exact same issue with my 2017. Unfortunately, I had to show a previous post from this forum to the dealer before they figured it out.

 

[FordTechOne]

Please post the part number for said IWE check valve. Sounds like something I might wanna keep in the glovebox as a spare.
Thanks.

The updated part number for 2015-2018 models is FL3Z-3A788-B. It comes as a tube assembly; retail price is $9.90.