98' xc 70 transmission woes, or whoa !!

[Onespeed]

hi , been a member for a while 1st time to post ,
got a weird issue with our 98' xc
it goes like this , car will run and drive , when leaving from a stop there is a slight shudder then the car gets it self together and goes , when up to highway speed and you lift the accelerator it will make a slight whining noise from the front of the car ( about where the trans mission is ) when I stop the car all 4 brakes are hot!! and the viscous coupling is hot too , I ran the test for the coupling and the test for the freewheel , both worked -ish I then removed the propshaft , hopped in the car to take it for a spin , nothing... but a slight ratcheting sound from the front wheels , so I put the propshaft back in and it moved front and back with the same symptoms as in the beginning of the post , so here's my question , is it possible for the transmission to fail and not affect the bevel gear ? could the differential go bad but the transmission still run the bevel gear ?
any help or thoughts are appreciated
thanks, Robert