Torsen front axle problems ! anyone else ???

[Hockster]

Thanks for this-

1. Mid perch. All work done by the guys at SDHQ in Arizona, so a reputable shop that knows what it is doing. No changes to the settings recently.
2. Ideally, I would use 4WD every day- I bought the truck as a toy for the desert out here in Dubai. In practice, it has been sick for most of the time that I have owned it (and I didn't go offroad at all for the first few months I had it due to an unrelated back operation…). Since October, I have used 4WD a couple of times per week. I have only done 5 or 6 proper day trips in the desert.
3. I have never engaged 4WD under load. I have engaged on the fly, but always with no power on.
4. The problem only occurs in 4WD and we have narrowed it to the front end. Do you mean gearbox problem or something in the differential? Ring & Pinion etc were all ok...

You need to make sure the vacuum servo is getting vacuum all the time when in 4wd. If possible get a separate vacuum pump and test the servo making sure it is not leaking. This is what I would lean towards

 

[Rorywg]

Thanks Hockster- much appreciated. We tested the vacuum lines and they are holding a steady strong vacuum when the vacuum is activated.

I confess that I don't really understand how this would be a factor anyway- I thought the vacuum was only an issue in 2WD- i.e., that the way the system is designed, you activate 2WD and the default is 4WD. So if the vacuum is released, the IWE will lock into 4WD?

When we disconnected the vacuum lines, we drove the truck in 4WD and 2 WD.

In 2WD with the lines disconnected (i.e. axles etc turning but no power being passed through t case and differential) -> no clunk

In 4WD with the lines disconnected (i.e., power being transmitted through transfer case, differential and axles) -> clunk!

 

[Stepside]

Just from the video and this is purely subjective.
It appears that when the gears are engaged or let's say 'a load put on them'
That tolerances change - causing 'out or spec' condition.
That would indicate Not a fault of owner, but a FACTORY problem.
The fix sometimes becomes political, as Management does Not concede to Engineering data and/or recommendations.

 

[ITSALLGOOD]

Still a major unresolved issue Ford .....?

Thanks Hockster- much appreciated. We tested the vacuum lines and they are holding a steady strong vacuum when the vacuum is activated.

I confess that I don't really understand how this would be a factor anyway- I thought the vacuum was only an issue in 2WD- i.e., that the way the system is designed, you activate 2WD and the default is 4WD. So if the vacuum is released, the IWE will lock into 4WD?

When we disconnected the vacuum lines, we drove the truck in 4WD and 2 WD.

In 2WD with the lines disconnected (i.e. axles etc turning but no power being passed through t case and differential) -> no clunk

In 4WD with the lines disconnected (i.e., power being transmitted through transfer case, differential and axles) -> clunk!

Welcome to the Clunk Club ! If you find a solution please post it .

 

[Rorywg]

small update- i went back to Ford to run some diagnostics on the transfer case. They said it is fine. Then they looked again at the front end. While I was there, I looked at the hubs and realised that the hub, which they were supposed to have replaced a month ago, was still the old one (slight surface rust, marks etc). Of course, they charged me for replacing it etc… so they have now switched out the hub and actuator again. Problem gone.

Today, I was out trying the 4WD. The clunk comes back. There is also a rattle from the front end which goes away in 2WD. My theory is that I have blown yet another IWE, and that there is probably a leak in the vacuum line that is causing the IWE to partially engage and causing the damage.

Any ideas?!

 

[wanderfalk]

the best explanation i have hear is that the vacuum lines have small leaks that are not detected when idling because this is when it is at its highest level of vacuum. however when it is under load the vacuum drops and the micro holes in the line are enough to allow the iwe to partially engage. so at times you may be driving around under load not in 4wheel drive but the iwe is rounding itself off. the tech is testing while idling when in reality the leak is being masked. beautiful right. so now change the iwe and the lines. i think we need to drive around with extras (iwe) hanging from the key chain.

---------- Post added at 08:34 AM ---------- Previous post was at 08:32 AM ----------

there is not a service bulletin on this wow

 

[Rorywg]

thanks- i think you must be right. What is amazing is that this is over a month and thousands of $ wasted so far.

Can you explain why the vacuum drops under load? Someone else mentioned this to me but I didn't understand what/why/how...

 

[AUH1]

the best explanation i have hear is that the vacuum lines have small leaks that are not detected when idling because this is when it is at its highest level of vacuum. however when it is under load the vacuum drops and the micro holes in the line are enough to allow the iwe to partially engage. so at times you may be driving around under load not in 4wheel drive but the iwe is rounding itself off. the tech is testing while idling when in reality the leak is being masked. beautiful right. so now change the iwe and the lines. i think we need to drive around with extras (iwe) hanging from the key chain.

---------- Post added at 08:34 AM ---------- Previous post was at 08:32 AM ----------

there is not a service bulletin on this wow

Does this apply to 2011 models too? Mine doesn't have the torsen front diff but I get a loud clunk from the from left wheel that feels like the drive shaft is disengaging and reengaging. I have broken a driveshaft and a cv joint (see my thread on this) and I believe it is due to this problem.

 

[rojo212]

Could this be a problem associated whith changing to mid perch?

 

[Ms. MI Raptor]

My truck is stock - no mid perch and has this issue.