ON my dads '06 was doing 80 on the freeway climbing up a hill, when he topped out he backed off and felt an "out of balance" vibration. Slowed to 70 and BOOM...............at the dealer now waiting for a new NP273

 

One more shot..

 

and.......................

 

Wow! That could have easily caused an accident.. Glad you didn't mention one. Anybody offer a guess as to how or why this happened?

 

So was the 4x4 engaged?

 

Wow!

Cannot see how that happened in 2wd, I see the chain is still intact... that's nuts!

Josh

 

By the discoloration on the shifter fork, it looks like something got hot and froze up. Whatever..........holy ****.....

 

Yes, fortunately no accident but it did start a fire on the side of the freeway. Too soon to tell what caused it...I didn't get to spend too much time looking at it, he's 75 and it was a little warm in Palm Springs where it happened so I had to get him home.

 

I have a friend that the exact same thing happened to a few years ago, towing fifth wheel and climbing a mountain, kaboom. 4x4 wasn't engaged with him either.

I seem to remember that it was blamed on a manufacturing defect within the case.

 

No on the 4x4 being engaged, and not sure the chain is still complete. I'm thinking rear u joint came apart.

 

UPDATE!

Turns out it was not the rear u joint on the DS. Looks like the hubs were engaged. Either someone stole his front HD hub caps and engaged the hubs or they have been engaged ever since he bought the truck.
He has not turned the hubs himself as he cannot get down low enough due to physical limitations, has ran it in 4wd but used the vacuum switch.
Really sucks...he was kicking himself for being ignorant and not checking but I told him not to beat himself up as there have been 2 different mechanics that went through it since he bought it and both of them missed the hubs being engaged if it wasn't someone playing a nasty joke and turning them while he was in a parking lot or ?

There was light at the end of the tunnel, I asked him if he had comprehensive insurance and he did. Long story short= the insurance covered the damages due to vandalism, $250 deductible.

CHECK YOUR HUBS REGULARLY! If they were engaged when he bought it he has driven over 5000 miles with them engaged!

 

Maybe a dumb question, but why would running with the hubs on but in 2WD do this? I'm asking because i drive short distances with them on and was going to do it whenever we get snow - its cold when you have to get out, and the wife has rheumatism so its hard for her to turn them anyway

 

Just running the hubs without it being in 4x4, according to the switch did not hurt it.


That is not the cause.

 

From my own investigating and talking to the service writer when the front right hub is engaged it will cause the motion of the front right wheel to spin the front drive shaft which in turn spins the internal tc parts that are not designed to be spun at highway speeds. He put on 5k almost all of which was highway speeds of 70-90!

I don't believe driving around town for short distances does any harm, in fact I've heard many say it's a good idea to do once in a while. I do the same thing when hunting for 2 weeks at a time I leave them engaged until I know I'm done trail driving and highway is all I'll see.

Something else to think about....what does the manual say about top speed in 4H? Pretty certain it's not 70-90. With the hubs engaged and in 2H the driveshaft is turning the tc as opposed to when in 4H the tc is turning the driveshaft.

 

I would venture to say the TC was never serviced...therefore low on lube.


right front wheel, left front wheel...either or both will turn the front driveshaft.


I think your "mechanic" is a little rough there.