Can not figure this out.

[powerranger262]

02 FX4 Automatic, 92,000 miles. I've been having this ongoing problem for a while now and it's getting really f'n frustrating. I have a bad jerk when it is under load when shifting into OD, this has been going on for about 10,000 miles now. There is also a slipping feeling when hard on the gas at takeoff, otherwise it's not there. When I look in the rearview mirror while going about 45mph, the rear of the truck is shaking like nuts. Also just got a humming noise that just started last week. It is only there when accelerating, and gets a higher pitch the faster I go. This all sounds like something driveline related, but where the F do I start?
Things I've replaced within the last 15,000 miles:
Plugs, wires, air filter, fuel filter, cleaned throttle body and MAF, new IAC, new TPS, dropped pan and changed trans fluid and filter, added a bottle of Lucas stop slip, changed rear diff fluid, refilled with synthetic, replaced U joints, greased slip yoke, and new Idler and tensioner pullies.
I have no CEL's and the engine runs great. Help or it's going over the cliff.

 

[fordman4x492]

have you hauled any big loads long distance in overdrive? that might be the cause of the humming noise.

 

[adsm08]

Some vibrations you just need a vibration analyzer for. Might want to take it to a shop.

 

[BRUTUS_T_HOG]

what is the condition of the transmission fluid?

 

[adsm08]

He said he changed it not too long ago.

Did you drain the converter?

 

[powerranger262]

Did you drain the converter?

No, I just dropped the pan, let the fluid drain out, replaced the filter and filled back up.
I just got back from a drive and the humming noise is really loud at 35-40mph.

 

[powerranger262]

have you hauled any big loads long distance in overdrive?

No.

 

[powerranger262]

BUMP
The shake that causes the back of the truck to shake happens when I let off the gas.

 

[BlackBII]

Have you done anything to the rear to lift it?

You said you replaced the u joints, did you replace all of them in the rear driveshaft? Also, how's your pinion angle look? Any broken leaf springs or hangers? When you let off the gas, the pinion angle could be changing, causing the vibration in the drive shaft

 

[powerranger262]

did you replace all of them in the rear driveshaft?

^ Yes, I did the two on the driveshaft, marked everything out so it went back together the same. No lift in the rear. I just got back from another drive, it's shaking at 2,000 rpms bad when I am really light on the gas. If I stay lightly on it, it starts bucking a lot until I lift off the gas and touch it again to downshift. Torque converter? Valve body gasket?
I've been reading a little about a shift kit. Anybody do this and what did it fix?
It's going to have to go to the shop whenever I can find the time between buying a house and being swamped with work. Still hoping to find a somewhat easy fix.

 

[powerranger262]

On another drive, I tried going through each gear to find the humming noise. When in 1 it starts at 35mph, in 2 it starts at 35mph, and D and OD it starts at 35mph.
It is hard to tell where it is coming from, but I'm pretty sure it's the rearend. Anyone have their POS torsen blow up on them? What did it do before it grenaded on you?
Of course the recall on them are only for the manual trans. because the automatics can't put out enough torque to wreck it, YEAH RIGHT FORD.
Also, yesterday when making a sharp left turn out of a driveway, the rearend clunked like something was locking or unlocking in it. It did this once before when I was backing up and turning hard to the right also. WTF is that now.