Low groan within the core of the world

[eo1sc]

Hello everyone I just became the happy owner of a 2002 Ex with the 7.3. I must say i have put over 400 miles on her and she now has 117,000 on the odo. Here is my problem. I have already cruised through the postings about this and I believe that it might not be so easy to find. This is what goes on. From about 20mph up to 50 mph there is a groan like a bearing noise on a front wheel drive car. When I accelerate or deccelerate it remains constant, however, when the truck is put into neutral at speed, it goes away. There is no dicernable vibration, just this annoying sound. Actually it sounds more like the gear drive on a 6.2 chevy diesel, but without the whine and, coming from the rear. There is also no leaks anywhere on any of the seals. I will be climbing under her in the next couple of days to change out the dif fluids, and check out the ujoints.
Would my rear end be going bad?
Can I lose bearings in the transfer case without any leakage?
Can I lose the rear wheel bearings without any leakage?
Maybe I'm overreacting and it could be coming from the front and actually be the IP but I have a long trip from Wa to PA coming up and I don't want to get stuck in BFE. Other than that, this truck is in excellent shape, 1 onwer, maintained to excellent standards, which led me to purchase this baby.
I hear this same noise in the big 6x6 military trucks so maybe I'm worrying too much, but like I said I have a long trip coming up.
Oh, I must say i love the low 20's for fuel mileage!! Much nicer than the 05 Ram with the Hemi I just unloaded.

[vitalidle]

Hmm not sure maybe a carrier bearing Those are always hard to pinpoint, but has to be somthing in the drivetrain I would believe.

[eo1sc]

Okay, I pulled the rear wheels and rotors, no signs of leakage, changed the dif oil and the bearings/gears look good, the driveshaft does not have any signs of grease slinging, or movement.
When the torque convertor goes bad, what kind of sound does that make? Is there any vibration that comes with it?

[CSIPSD]

Originally Posted by vitalidle

Hmm not sure maybe a carrier bearing Those are always hard to pinpoint, but has to be somthing in the drivetrain I would believe.

No carrier bearing on the X...

Could be a drive line issue, could be a TC issue. Are you lifted at all?

[vitalidle]

Originally Posted by CSIPSD

No carrier bearing on the X...

Good to know as I did not know that

[mrnecsteve]

The symptoms you describe,match the symptoms of when a ujoint is just starting to go bad.Typically ,one end cap has the roller bearings go bad first.The ujoint is then able to FLEX under load.Until it gets really bad and looses the other end cap,it is often difficult to isolate without pulling the driveshaft out.
If you do pull it ,dont forget to lift the back end or lower the front to keep from loosing tranny fluid.
With the ,mileage on your truck and the oem ujoints not being greasable,i would expect them to be a little worn right now. I would change them as a preventative maintenance
item. Its a worthwhile investment if your willing to do yourself.Ask for ujoints with a grease fitting or Zerk fiitting. You can have a machine shop press them in for you...or as I do....use a humongous c-clamp to press them in.

[eo1sc]

I'm not lifted and the only time I had ujoints fail, they got clunky, but your right though, I'm gonna replace them anyway since I have so many miles on her, other than the groan, she is so much fun to drive!! It;s like riding around in a big couch! Now if I can only locate those springs for the front, they are the b code f350 ones right?. I like the stock height, so I'm not in a hurry to lift it,

[eo1sc]

Well, she's at the dealer now. I tried to switch the programming from performance to Tow safe and the Pats system was reset, unfortunatley I do not have another key to reset the system. Funny thing though, I chaned the programming before and this did not hapen. It's a Superchips programmer if anyone is interested.