I thought the same thing, after the dealership dissected the tc due to the insurance company requesting their inspector verify the cause it was determined to be a buildup of excessive heat in the tc and it seized. Don Naslund' post headed the right direction on this one. The front drive shaft will spin on it's own in 2H w/out hubs engaged but is different from being forced by the wheel spin.

 

All fluids were checked/ changed right after he purchased, even had coolant drained/ flushed, oil, fuel, filters, trans fluid changed, tc checked, diff's changed. The dealership he purchased from bought this at an auction and paid for a post auction inspection of which it failed so the winning bid was not forced.
He went back 2 weeks later and the owner fixed the issue that caused it to fail originally (turbo related) and this time around it passed the post auction inspection.
Dealer paid (at my dads and my request) to have it gone through by a local mechanic and it checked out, he purchased and had the same mechanic change and check all fluids before he started road tripping his new truck. 5000 miles later and boom! I'm leaning towards the hubs being engaged at the auction from people checking things out on it and they were never turned back and was overlooked (easy to do ) by everyone involved.

 

I thought neither left or front would turn the d shaft in 2H until I checked on my truck, turns out it is the right front and not the left (unless LS is engaged) that will lock the drive shaft when the hub is put in manual.

 

The manual doesn't mention speeds specifically, it just says don't change from 4H to 2H at speeds greater than 55mph. It also says that switching the hubs to free is just to save fuel, so me leaving them on lock won't be a problem. Maybe I should RTFM a bit more often...

 

I thought I read a sticker or manual that had recommended speed limits in it, must have been for another vehicle?

Now I'm wondering if the problem was the rear u joint on the front drive shaft, could have come apart being spun at 90 and it did need to be replaced after this incident. But why the signs of excessive heat in the tc? Maybe the dealer/inspector didn't know what they were talking about.
I doubt the front drive shaft is balanced for that hi of speed so this could be an option.

 

Maybe the front driveshaft seal on the transfer case failed due to the bad u-joint vibration at 80mph....seal leaked the fluid....Got hot, then grenaded the transfer case?

The front driveshaft is wet, could the fluid blow forward at highway speeds?

 

Personally I would say it was low or improper fluid in the transfer case.

 

Since the fluid was changed 5000 miles ago, it sounds plausible that they might have put in the wrong stuff - it happens.

 

This happened to me and it was my fault becuase when I left the dealer after purchasing my 6.0, I turned the hubs to make sure they weren't frozen. They weren't, but in my haste to inspect the vehicle, I forgot to unlock the hubs and for the longest, drove with the hubs locked.

Mr.Gearhead suggested that this might be why my mileage was so low even with his tunes and he was correct. I drove for almost 2 months with hubs locked and averaged 13-14 mpg, as soon as I unlocked them, my mileage went up to 15-18 mpg.

So I'm leaning towards the hubs being locked as well. Regardless, glad it didn't cause an accident.

 

There are plenty of guys running 100K+ with hubs locked in 2wd. And even more that lock their hubs in October and unlock in May.

The hubs weren't the issue.

Josh

 

Good to know, wish I could rep you from my phone.

 

FWIW the NP273 was also installed in Dodge's with full time hubs.

Can definitely see the "bluing" of parts due to heat. Why is the question and the recent "service" would be the suspect.

Josh

 

I've put 40,000miles on my 06 f350 since I bought it and have never unlocked the hubs. In 2wd there is virtually no load other than what it takes to spin the extra parts but if those extra parts have no lubrication they will get hot. With the carnage in the pictures there should have been lots of oil over every thing if there was any oil in it?

 

I am thinking low fluid levels.

One thing I see or more to the point don't see. There is not a lot
of oil on things. 2 Qts of fluid should make more of a mess.

Also one other thought was any teflon tape used on the
plugs? The transfer case in the truck has a pump to move
fluid to the bearings. If any tape got into the pump that
could reduce the flow and with the front driveline spinning
add more load and heat.

Sean

 

I bought a sd that did thst too. Check trabns for holes or cracks on front ds side AS mine had a big hole in trans