If you have seen the frames that have bent on YouTube you will notice that it bends at the bump stops. Or at the first hole in the frame just after the bump stop. If you look at the frame you will notice it gets smaller at the wheel arches. And GM wants it to bend down in a rear end crash.
Also these trucks have a soft rear suspension that is easily bottomed out over just a dip in the road. You have multiple issues here.
I do believe the frame is a weak spot. And poorly engineered.
I watched an interview from a design metal technical guy about these frames. They also work with and supply metal technology to other car companies that also had complaints of bent frames. This guy says the frame is very strong and computer designed. BULL SHIIT........
The problem is that a large load (at the tail of the truck) may bend the frame. But if the weight is close to the cab there will be no issues.... But a heavy load at the tail will cause a bottom out situation and the frame will bend down. IpIt will not bend from just the weight but from the sudden stop when the bump stop suddenly stops the suspension.
I have have overloaded my truck way beyond the it’s load limits.
I had the bed loaded with hard wood and a Big dump trailer full of hard wood connected with over 8,000 lbs. That had a 1000 lbs tongue weight.
But I took the long slow road home as not to hammer the suspension on those bump stops.
Also a load like a drop in camper puts a lot of weight at the tail.
That and the high center of gravity of a drop in camper along with the soft suspension may cause serious handling issues in a emergency situation.....
But for GM to say a drop in camper will void the warranty is an obvious admission to a poorly engineered frame.
And what really kills me is that when the word gets, out and it has got out. and sales drop off.
GM will say sales were to low to continue building the trucks. No one wants a mid size truck......
Its the same with the diesel 2.8
I truly believe the reason for discontinuing the 2.8 is high warranty issues with plugged DPFs and plugged DEF injectors ect.
And it effects the sales of there new 3.0 diesel full sized truck.
Dont forget the new 3.0 litre has the DPF very close to the exhaust manifold and that helps keep it hot and clean.