Curious. Why is rear axle offset to passenger side?
I recently purchased a 2016 Colorado LT crew cab with 4 wheel drive and the diesel engine from an insurance auction. The truck was involved in a front passenger side collision where the driver airbag went off. The main body damage was the passenger fender was "peeled" back toward the rear, with some secondary dents on the passenger front door and scuffs/minor dents on other areas of the truck.
Had the truck up on jackstands while surveying the underside to determine if there was any frame damage and noticed that the rear axle was offset about 1.5 inches to 2 inches to the passenger side. That is, if I sighted down the side of the truck and compared the outside surface of the rear wheel to the driver and passenger rear wheel fender, I could see that the rear passenger tire exterior surface was about flush to the outside surface of the rear fender and the rear driver's tire exterior surface was recessed about ~1.5 to 2 inches from the surface of the driver side rear fender.
My initial thought was some frame damage. However, I concluded that it came from the factory this way for the following reasons:
1) took various reference dimensions from the rear axle to the various points on the frame, and compared driver side to passenger side (that is, axle location relative to the front end of the vehicle). Saw basically no difference
2) there was no visible sign of any damage to the frame (no paint scratches, no buckling, no dings, etc)
3) there was no visible sign of any damage to the rear axle mounting points at the frame or on the rear axle (no paint scratches, no buckling, no dings)
4) measured from the inside edge of the rear wheel to the outside edge of the frame and found that it was almost 2" more on the passenger side than the driver side (which again one could visible see when sighting down the side of both the passenger side and driver side)
5) was scratching my head as I was not seeing any obvious reasons why visible offset of the rear axle, as the rear axle has a "mounting pin" for locating on the rear leaf springs, so there is no "adjustment left or right on the rear axle mounting location
6) and finally, when I was at the Chevy dealer getting some parts, I looked at a Canyon crew cab with the diesel engine and found the same condition (that is, when I sighted down the side, I could see the passenger rear tire was about flush to the rear fender and the driver side rear tire had about a ~2" clearance from the surface of the rear fender).
So all the above reasons is why I concluded it came from the factory this way
So why would GM design the rear axle location to be slightly off center, when compared to the outside body surface? I do not know if this is unique to the diesel/crew cab or if it applies to all configurations (I only looked at a new diesel crew cab a the Chevy dealer)
So again, just curious, why the difference. Any thoughts?