One problem related to structure has been reported for the 2000 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2000 GMC Sierra 1500 based on all problems reported for the 2000 Sierra 1500.
Excessive rust from middle of under carriage on back lead part failures. One of two straps holding up gas tank, rear strap, broke and rear of gas tank dropped about 4 inches. I was not driving the truck, just noticed then gasped. I replaced the gas tank strap. Research on internet reveals excessive rust for these trucks is common. After hearing about the Toyota tundras dropping a spare tire due to excessive rust, I figure a part failure possibly leading to a dropping a gas tank qualifies too.