Problems with 2008 GMC Sierra 1500 SUSPENSION

Took 2008 gmc sierra 1500 4x4 to tire store to rotate tires. they indicated that the lower front ball joints were loose. this truck has 77,000 miles so i was skeptical. took truck to gmc dealer for service & requested that they check the lower front ball joints. they indicated that the ball joints had one quarter of an inch of vertical play and were indeed loose & needed replacement. i have earlier gmc trucks with over 200,000 miles and have not had worn lower ball joints. i believe that the looseness is due to the ball joint pulling apart. the wear was not side to side as would be expected. i want to repair this defect so as to avoid a catastrophic failure of the front suspension. i want to use oem parts but i am concerned that these ball joints are defective. the gmc dealer advises that even though the truck has a 100,000 mile power train warranty, the ball joints are not covered. *tr

2008 gmc sierra 1500. consumer writes in regards to thump under the right rear wheel *tgw the consumer was informed the front differential had a crack in it and the rear middle leaf spring was broken. *jb

Truck shakes between 45 and 60. does it all the time. took to gmc dealer and they check it out and said it was the way the truck was get used to it. called detroit and got the same thing. it's not right. it all started with around 14,000 miles .the truck didn't do it at all until then. the service station that i use to service it found the tires to be out of round and the sidewalls were coming undone. put a new set of tires on and it helped a little bit but not a great deal. they also told me to put weight in the box to help. i tried and it didn't help. all i want is the truck made right. *tr