First of all, i have a 2004 F250 4x4, automatic, 150,000 miles. I have a "whinning / fine grinding type noise when i'm driving. I jacked up the pumpkin and had a friend put in drive while i listened. The noise seemed to be coming from the transfer case. I switched out the fluid with 2 quarts of ATF today, no change.
Can i add some Luca oil to it? would it help, or am i looking at a new t-case?
If a new case, any suggestions on where to buy?
Is this something i can easily change out in the driveway?

any suggestions would be greatly appreciated.

Thanks,
Frank

 

Did you get anything solid when you drained the fluid?

Hopefully you put in a Mercon spec ATF but I suspect you did. I would doubt that if you're getting a grinding noise that just adding lucas is the right thing to do. I suspect you actually have a problem with the transfer case that will need to be repaired out of vehicle. That being said, by all means drop some lucas in there if you've got some on hand. I doubt it could hurt, but I wouldn't put my hopes in it.

From what I read from my Ford DVD and Haynes manual, this process could be done in your driveway with nothing more than a 1/2" impact and some jack stands (on the electronic shift model). To sum up a long list of steps:

1.) Jack the truck up on jackstands.
2.) Take out all skidplates covering the t-case.
3.) Unbolt the t-case cross member.
4.) Unplug the electric connector going to the t-case.
5.) Disconnect the front and rear u-joints.
6.) Unbolt that SOB.

I've never held one from a Super Duty but I suspect this case is pretty stout. You'd probably want a transmission jack on hand or a few buddies to help you muscle this thing out from under the truck.

If you decide to remove the t-case, a rebuild will likely cost you an arm and a leg. I'd just search a junk yard for a used one, and inspect it before I purchased it.

I hope this helps!

 

That noise could be coming from anywhere and resonating through to the transfer case.

Remove the rear driveshaft and see if it still makes noise.

Do you have a hanger bearing in the middle of the driveshaft? They are known to go bad and make that noise you describe, and it could resonate through and sound like the transfer case.

Otherwise, the output bearing is probably bad in the transfer case and is not TOO hard to change out yourself, if you have the right tools to get the rear flange off.

 

I have a device that you may be able to pick up at a parts store. It is a like a doctors Stethoscope except the end is pointed. You can them listen internally to what is happening.

Might see if you can find one and do that.