4 Wheel Drive/SUVs: 2003 sport trac, wheel bearings, rear brakes

Question
QUESTION: I have a very annoying, repetitive squeak coming from the rear end of my sport trac.  It is most prominent at low rpm's and then tends to disappear when I pick up speed.  I had my mechanic look at it and he thinks it is the u-joint.  He told me he lubed it up well and we should wait and see if the grease can work its way in.  If not, it should be replaced.  Im finding it difficult to believe it to be the u-joint already seeing as it only has 110,000 km on the chassis.  Is this normal?  Could it be something else??

ANSWER: i would personally check the wheel bearings, and brake assemblies.

---------- FOLLOW-UP ----------

QUESTION: Rear brakes were completely redone during the last trip.  Do you agree that its a little early for the u-joint to be worn?      There is hitch on the truck.  I've never towed with it, but maybe the prior owner did.  Would this make a difference?

Answer
u joints can go at any time wheather its at 5 miles or 50,000 miles, but normally u joints are on the front 4wheel drive axels, and the driveshafts only. which is why im questioning what he told you about the u joint. and the hitch shouldnt make any difference. I would take it to another mechanic and get a 2nd opinion on whats wrong. Because at this point I have no clue what it is.