96 awd 5.0 drivetrain prob.

[shellsb18]

Long post...I apologize.
Been reading and reading posts and am starting to feel it in my wallet.
256K. Wife LOVES this truck. It's been so trouble free we thought it would run forever. It is even almost rust free. Started to make some noise last week. Front drive shaft joint failed. Had it fixed. Noise was gone. Few days later it starts making noise again. (It's had the rear end hum noise for the last 160K...........Ford said don't worry about it then)
This noise is kind of a rumble/shudder. All four tires off the ground right now. Turning back tires slow (hand spin) gives me a rough sensation and front tire turns also. Turn tire fast and it turns easily and drive shaft doesn't turn. I understand that there is a clutch pack in the rearend housing and a viscous coupler in the transfer case. Where do I start??? Should I be able to break clutch discs free in rearend housing by spinning back tires by hand?
(I left the tires wear without rotating this year and am afraid I may have caused viscous coupler damage) How can I check for that?? Appreciate any help. Thank you

 

[safn1949]

Take the vehicle to a paved parking lot and do tight turns both ways,if the viscous clutch is seizing up it will jump and hop like mad,just like a regular 4x4 will.

You can put another transfer case in it or remove the front driveshaft if your emergency brake works.The truck will roll in park with no front shaft.

Also have you serviced the rearend ever,is it full of fluid? Is it a limited slip?Transfercase been serviced?

 

[shellsb18]

No wheel hop when turning. Been told by shop today that everything may have been caused by worn tires. I had just moved two fronts to rear. They were worn down more then rear ones. Am having new tires put on Friday.
Rear and front dif. serviced at around 175k. Transfer case around 150K just last week when I replaced front drive shaft. Hope it's as simple as tire size issues.