Hey Folks. My 2011 SD started clunking while in 4x4 this weekend. I was on an icy road for about 120 km driving about 60-80 kph and once or twice noticed a random clunk. Didn't think much of it.

Fast forward to following day - get truck on an icy hill where I had to make a sharp turn. Put truck in 4x4, turn off ATC by holding button 8 seconds. Only rear wheels engage. So then try 4 LO. Same thing. Straighten wheels, shift to park, engage 4x4 again and she hooks up and drives out no problem. Further down the road (still in 4x4), it fish tails slightly and then check 4x4 light comes on. In order to get 4x4 re-engaged (was spinning at a stop light on a slight incline) I had to shut truck off and restart it. Then it seemed to work normal and light went off.

Little further down the road I had to go up a steep incline and at a steady 40-50 kph I started hearing (and feeling) a noticeable clunk every few hundred feet. No idea what it is. Seems to be coming from rear of truck but honestly cannot say for sure. Goes away when in 2wd.

So, any ideas? I have 7000 kms left before warranty expires luckily.

Thanks, JC

 

So went to dealer today and it seems that I couldn't reproduce the issue. Maybe it's too warm back here in town (0 degrees). Tranny temps were around 88C today whereas when I noticed the problem they were at 66C. Anyway, I know it's not a temp specific issue because I drove the same road in a 2014 and that truck didn't do the same thing. So now I have no idea how I am going to prove this to the dealer. Ugh.

 

Pulled code. It says C1010, which is apparently the Continuous Vacuum Hublock (CVH). I guess they will see that on Monday when I take it in and hopefully they can just replace a solenoid and be done with it.

 

Let us know how you end up! I think this is the first we have heard for the vacuum system to be failing in these trucks, but it's not out of the question.

 

It's not all that out of the ordinary actually. A few have reported leaking vacuum operated hubs. The nice thing about our setup though, is that we can manually lock in the hubs and leave them that way for as long as we want with no ill effects other than a small drop in fuel mileage, and then engage or disengage the transfer case with the dash switch. If your hubs won't lock on "auto", try them in manual. I bet what you heard and felt was the hub locking and unlocking due to intermittent vacuum operation because of the leak.

 

I sure hope you're right and that's all it is.

 

Does anyone know if the check 4x4 light is always accompanied by a check engine light along with a C1010 code?

 

just a general statement but to keep your 4 X 4 system working you have to use it regularly. Did thousands of 4X miles while working for her majesty's prov. gov't without ever having a 4X failure. Other folks never engage the 4X for a year or two and guess what it often does not work.

When you get it sorted out exercise the 4X monthly at a minimum.

 

Well, it goes into the dealer tomorrow AM. I'll post back and let you all know what they have to say.

The (maybe) crappy part is that I haven't been able to replicate the problem even though temps are down around -20C again. Is it possible that because I drove so long that day in 4x4 @ -25C (120 kms or 70 mi) that something simply froze up and has since released?

JC

 

Sounds like what happened in my 2011 and it had an air leak. If you lock the hubs in manually (thankfully we have Fords that still have that ability) does it work? It was the only way I could get mine to engage in 4x4 until they replaced an air fitting.

 

Don't know. Haven't tried it yet because I have aftermarket wheels and can't get to the lockers without taking wheels off. There is a lesson learned...

 

Hey thejean,

Are you going to your dealer tomorrow morning (or did you go in today?) Send over the year, current odometer reading, and dealer diagnosis or update; I'll determine how to move forward.

Nikki
Ford Service CA

 

Thanks Nikki. I just got back from dealer. They were able to diagnose a leaking RF hub and bad seal. Replaced everything under warranty. Everything is good now. Cost to me $0, which is the best part. Gotta say, pretty happy that Ford decided to pull truck apart and check everything even though they couldn't reproduce the symptom. Definitely this kind of service makes a person become a blue oval fan. JC

 

Glad they got you fixed up!

 

Thanks for informing, thejean! Glad to hear everything worked out for you and that you had a great experience!

Kwasi and I will be around if you have any other questions or concerns; We're here to help.

Nikki
Ford Service CA