Picked Up a 00 Expedition XLT 5.4 w/A4WD, 4WH, 4WL. Noticed that it drives different from my 98 XLT 5.4 w/2H, A4WD,4WH, 4WL ?? I feel more of a vibration / trembling, in the 00 w/the all wheel drive, It's more noticable when
you step on it hard, and it does not have the pickup that the 98 has w/part time 4WD ? Is this normal for the AWD Expedition / Navigator?

BJW

 

Check the differential.Under hard acceleration you prob will feel a little something. I took my front drive shaft out because the differential is on the way out

 

Check your tires. With the AD system the tires have to be rotated often, or they start wearing funny. My 01 had a pretty good rumble when I got it, ended up it had three different brand of tires(all the same size). Once I switched to new tires, rumbling disappeared. Still get a little vibration on accell if it is slick.
YOu may want to change the diff and trans fluids as well. I did mine a few wees ago and it is smooth as silk now.