03 Expedition pulls hard left in 4Hi and slow to disengage

[Yoshi]

My 03 Expedition 5.4L Fx4 pulls hard left in 4Hi. sometimes has problems disengaging right away. in 2wd mode it doesn't pull at all.

 

[jkill351]

is it making any noise? ive heard of a problem with the vacuum that engages the front hubs. but that makes a horrible noise. my 03 disengages slowly but no pull actually it mostly just wants to go straight in 4x4