F250 Transfer Case Noise

[Bob and Renate]

Hi folks,
I have a 08 F250 Super Duty 4x4 diesel with12.5K miles on it. I never owned a 4x4 B/4 so therefore I can not make any comparison.
I have switched to 4x4 high for the first time this week for about 10 miles (extremely wet road conditions) and I have noticed an annoying noise coming from the transfer case. It is a constant hum, not to loud, I still can hear the radio but it gets on my nerve.
Is this normal when you in 4x4 or is there something wacko with my transfer case.

Thanks,

Bob

[bigbunkhouse]

Thats a hard one to diagnose, are you sure its the transfer case? the front end is all connected and carries the sounds thru all the touching metal ie----from hub to axle to gears to driveshaft to transfercase. Nothing should be loud enough to be a distraction under normal conditions, the newest thing I own is 99 so I cannot attest to the driving experiece in an 08, take it back to Ford and let them test it with their "chassis ears". What is your setup? auto 4x4 with switch on dash or floor shifted and manual or auto hubs? Don't rule out an ooops at the factory, My buddy whos property we use as a private campground 6 months a year had his 2000 f250 since new and doesnt drive far ever, after a few years the rear axle made more and more noise till it finally just wouldnt move, turned out there was NO fluid, ever, it was bone dry, no trace of fluid anywhere.

[Chief409]

I'd take it to the dealer. First I would make sure it IS out of 4WD, if the steering is stiff or feels like it is binding on tight turns 4WD is still engaged. And check your front hubs, make sure they are both set to Auto if you have the knob selector on the dash. I've had 4 4X4 Super Duty's, 2 2005's, a 2008 and the 'Beast, both my own and work, and have never experienced any noise from the transfer case. Driving with 4WD on a wet road shouldn't of caused a problem, however I don't recommend doing that. The surface you are driving on has to be loose to prevent wind up between the axles by allowing the tires to slip. A paved surface, even an extremely wet one, might not permit enough slipping, especially if you are making lots of turns.

Let us know how things turn out.

[gmarker]

Take it in to your dealer and make sure they describe exactly what your concern is on the repair order. If the dealer tells you that there is no problem with it but, you are not completely convinced, return it to the dealer again before the warranty expires and go through the same process, making sure that your concern is documented on the repair order. If a related failure then occurs after the warranty, you will have a much better case for goodwill consideration.

[BMullins46]

One thing you need to remember is that after you shift out o 4WD you might need to back up about 20' or so to get the 4WD disengaged especially since you were driving on pavement. I always had to do that when we got back to the pavement when we'd go 4 wheeling in our Land Cruiser, and my Company truck also needs to be backed to completely get out of 4WD.
Bill

[Chief409]

For my trucks I drive straight ahead after I go to 2WD for a bit. Backing the 'Bird up hill on the gravel driveway at home I have to use 4WD, if I forget to switch out before I get back on the street, and make the sharp turn to park the truck in front of the garage, the wind up between the axles caused by the turn keeps the transfer case from shifting to 2WD, and the herkey-jerky starts until I go straight and get the load on the transfer case off and the auto hubs freewheeling. About 10 - 20 feet going straight ahead is all it takes.

Lot's easier then the manual hubs and transfer cases I've wrestled with!

[Bob and Renate]

Thanks for the all the advise gents. I am pretty much aware of what to do and not. I have no problems getting in and out of 4 wheel drive, everything is working just fine. As soon as I switch in to 4x4, I can hear this annoying hum, after disengaging, it is back to normal. That’s why I believe it is coming from the transfer case. I will call the dealer to day and see what they have to say.

Bob

[pokypa]

Make sure the tire pressure is the same in all four tires. If one tire is low it will cause a ratio difference which will cause the transfer case to bind and cause a hum sound. The front rear is pulling one ratio and the rear rear is pulling difference. I had this same problem and after checking and fixing air pressure the sound went away. You won't hear the hum on a dirt road because the ratio will slip to keep it timed properly. The problem can be cause by different size tires on one axle also.

Pokypa

[Chief409]

The problem can be cause by different size tires on one axle also.Pokypa

Oh yeah, the big drawback of 4X4. One tire goes they ALL go if there is any wear at all on the remaining three. Or, you can get a replacement tire. A replacement has to be the same make, model, size and tread. And turned down to match the wear of the remaining tires. Lots of tire dealers won't do that though. But, with the new truck tires, and taking a reasonable amount of care to avoid road hazards, it isn't that much a problem. Rotate the tires every 5K and they all wear the same.

[rlhedlund]

I would not advise running in 4x4 on pavement, even if it is wet. Moreso even when it is wet. 4x4 is less stable traction-wise on pavement as the front and rear do not turn at the same ratio. Try the 4x4 on dirt and see if you get the same noise. The noise could be because you are fighting the gears against each other on pavement.

[Bob and Renate]

Noise is gone!!!!
I checked the fluid in the transfer case and it was next to nothing. Shortly after I purchased the truck, I noticed fluid coming out of the shaft bearing. The dealer replaced the bearing, but some body forgot to add some juice!!
I added fluid; called the dealer let them know about the great service, done deal.

Thanks,

Bob

[Mike Clay]

Well I dont think that is a good thing, they need to take a close look at that transfer case and replace it no oil for that long is not a good thing.

[bigbunkhouse]

Glad it is up and runnin quiet again, sounds strangely familiar, the no fluid thing and all. What did you use for fluid?

[BMullins46]

I agree with Mike. The dealership needs to check out the transfer case and replace any worn parts.
Bill