One problem related to frame rust has been reported for the 2005 Chevrolet Colorado. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Chevrolet Colorado based on all problems reported for the 2005 Colorado.
Driving on expressway at 65 mph. Truck seemed to lock up parking brake and began to swerve. Car behind me tried to avoid hitting me and swerved into other lane, barely missing a collision himself. Nursed truck home. Took to my mechanic and explained what happened. In the parking lot of service center he crawled under to check parking brake cable and immediately noticed my frame had broken on both sides! this truck, seriously, is in show room condition. Mechanic checked rocker panels, fenders, under bed and floorboards and said there is no rust anywhere except on your frame. I baby this truck as I am 71, retired, on pension and social security and vet. This car is washed at least once a week and in the winter it gets washed twice a week. It has been waxed eleven time in the past year, August of 2017 thru September of 2018. Manufactures recommended services are all up to date or even exceeded. Internet shows this as a complaint with many 2004 - 2006 Colorado having rusted out frames and GMC is not willing to do anything about it. They should learn from Toyota how they took care of their customers with rusted out frames. This is a serious safety hazard. When these frames break as min did it slows down quickly and will swerve. I think the slow down is caused probably with the twisting of the body or the bed and possible strain on the differential or axle. Just a guess. Luckily, the car behind me was able to swerve out of my way, but just about hit a person in the lane he swerved into. This truck is garage kept and I only average about 4000 to 5,000 mile a year. And seriously this truck looks like it came off the show room floor.