One problem related to carrier/rack has been reported for the 2005 Chevrolet Avalanche. The most recently reported issues are listed below.
I own a 2005 chevy Avalanche. At about 125k miles on the odometer I noticed that my speedometer would start to gradually lose track of the speed after driving for approximately 40 - 60 miles. So, when travelling at a consistent rate of speed of, say, 60 mph the speedometer would slow down gradually to zero over the course of 5 - 10 miles. When the vehicle was turned off for a period of time the speedometer would reset itself. Once reset it may start having the same problem immediately or it might be another week or two before this problem presented itself again. I took the vehicle and was told that the "cluster" would need to be replaced for approx. $600. Judging from the other complaints registered here, I believe this should be fixed by the manufacturer at no charge to the owner regardless of the mileage.