Review on Dorman 604 113 Air Door Actuator by Shane Picot

This unit is quite different from the genuine GM part. On the one hand, the case appears to be made of thinner plastic, and it snaps in rather than screws. Second, the internal gears appear to be made out of a different type of plastic, but I can't tell if that's a negative or a positive. I'm hoping for a positive result in the sense that the gears don't break or crack as is common with genuine parts. Finally, and most importantly to me, the metal shaft sleeve is a different size and has grooves (which isn't really necessary considering how this thing attaches to the plastic shaft). However, the difference in the size of the metal shaft sleeve is a real PITA as it is slightly smaller as it is microns smaller so it is very difficult to visually tell the difference. As a result, the metal shaft sleeve does not slide over the plastic shaft without great effort; and considering where this part is mounted in the car, it's almost impossible to apply force to it to put it in place. What I did to solve this dilemma, after struggling with the installation for almost two hours, was I grabbed some plastic shaft sandpaper (not on this drive, but on the part that actually goes in). In doing so, he chipped off the tiny burrs that slip into the grooves of the shaft sleeve (which again are useless on this drive because it can only move in one direction). Once I did that, the drive was in place and I was good to go. Unfortunately this did not solve my initial problem with HVAC air blowing random vents as possessed (rotating between floor, defroster and dash vents) even after numerous reprogramming events with the ECM and drive reconfiguration. In my case I think the auto HVAC mode on the control box itself must be bad.