Sierra / Silverado Cab Vent Cover

thingiverse

For all my brothers and sisters with GM trucks (GM, GMC, Chevrolet, etc.) that have had leaking rear cab vents, I offer you this! In many cases, not only does the outer seal on the cab vent dry rot and start to leak, the rubberized vent flaps also tend to break, fall apart, or otherwise fall off, leaving gaping holes through which water enters the back of your truck and floods the carpet. If you've seen the back of the vent, there is a frame that has what looks like four mounting holes, and it seems like the engineers originally thought, "Hey, we'll add a cover to this so that if the flaps ever fall off, at least there's not a gaping 3x9 inch waterfall waiting to happen", but someone else thought that the extra $2 per truck was a waste of money. At any rate... I've designed these covers to fit over the standard GM cab vent assembly. As far as I can tell, the same vents are used on trucks from 1999 to 2021, so there's a good chance this will work for you. There are three files: one single piece cover for those with larger beds, and a two-piece cover for those with smaller beds. I would glue the two pieces together at the overlap, then attach to the vent assembly with silicone, which will act as a glue and of course a waterproof sealant. The parts fit snugly to each other, and to the vent assembly. In my case, I chose not to buy new vents at $20 each, I picked up a door sweep from Lowe's, cut the vinyl into the right size, and used contact cement to replace the flaps. Cost about $12 total. I would suggest using PETG, as PLA doesn't seem to hold up well to heat and moisture outside. Print them flat side down and you don't need supports. March 22, 2021: one final note on assembly - the thickness of the current cover makes it a pretty snug fit when pushing the vents back up from the bottom between the cab and bed. In my case, it was actually a benefit, because I was able to move the vents into place from below and it stayed put while I got back inside the truck and maneuvered it into final position and click it in. I may upload a slightly thinner model.