The side mirrors on your GMC are pretty handy, especially if you've got the big tow mirrors with power controls and defrosters. Unfortunately, the side mirrors do stick out from the side of the vehicle (quite a bit if they're the tow mirrors), and that makes them vulnerable to damage from passing vehicles, tree branches, and the occasional garage.
If you need to replace an outside mirror on your GMC, we've got a quick tutorial for you below. All you need is some tools and a replacement mirror (OEM of course, especially if you want to make sure that you don't have any noisy air leaks that after-market mirrors are famous for).
- Standard screwdriver
- Standard sockets
- Door trim removal tool - trim is held in place with clips, and this tool assists in clip removal
- Door handle removal tool for crank handles – a crank handle has a spring clip, and by using this tool, it is easier to pull the crank off the spline.
- Replacement mirror
- Masking tape
- Matching automotive paint
- Door clips in case some break
If your replacement mirror is unpainted, you need to paint it to match or paint it black. You will find the paint code for your GMC on the information label, which is normally located on the driver’s door edge. You may be able to buy the paint in a spray can at an automotive parts store.
You can also check in with your local body shop about painting your mirrors to match your vehicle. It's surprisingly affordable, especially if you don't mind waiting a few days for them to fit in the paint work. Call some of the busier shops, let them know you're flexible in terms of turn-around, and they might be able to paint your mirrors at the same time they're painting someone else's vehicle the same color.
If you paint the mirrors yourself, be sure to mask the mirror to cover the glass and any turn signal lens that may be on the mirror. You can use regular masking tape, but painter’s masking tape is thicker. Trim up the edges of the tape so that they line up with the edges of the mirror and signals. If you are not careful during the masking, you can end up with overspray on the mirror or gaps where there should have been paint.
Hang the mirror up and rapidly shoot it with a thin, even coat of paint. Let it dry fully before adding another coat. You may need to add several coats to get the look you want. By moving quickly, you eliminate the possibility of the edges of the paint drying before you finish your pass.
Remove the Old Mirror
After you have gotten your replacement mirror ready, you can take the old one off the vehicle.
- Remove the trim panel on the GMC door by removing the screws or clips. You may need to look on the bottom of the door handle and inside the door handle for some of the hidden screws. You may also see a small cap that works as a screw cover. Pry those up.
- There may be a separate piece of trim that covers the mirror mounts. Remove it by taking the screws off or removing the clips.
- Pop off the GMC door panel by removing screws and clips. The trim tool will help you locate clips by sliding it between the panel and the door.
- Once you have the door panel loose, you will see the wiring that goes to the mirror and any other power equipment you have on the door. It is not necessary to disconnect anything but the mirror wiring.
- Remove the mirror by taking the mounting screws off the GMC. Keep it from falling and breaking.
- Disconnect the wiring to the mirror. Hold onto the wiring; you do not want it to slip into the door. You can tie it up to keep it from slipping inside.
Replacing the Mirror
- Connect the wiring to the new mirror and make sure that everything is put back into place.
- Put the new mirror in the proper position. Make sure that if you need to mount the base flange under the rubber window seal that you do that or risk your window not sealing properly. Attach the mirror with the screws.
- Check the mirror to be sure that it is operating properly before you replace the door trim. Turn the GMC on and try the mirror. If it does not work, make sure that you have it fully connected.
- Look at the door clips and make sure that they are not broken before you reinstall the door panel. Replace any broken clips.
- Put the door panel back on, and then put the mirror trim cover back in place. When you have it in place gently tap over the clip locations with your fist to make sure they are secure. Put all the screws back on the panel and replace the screw caps.
You can replace your GMC mirror in no time, and if you run into trouble, you can always contact your local dealership for assistance. Remember to paint your mirror before you mount it, as it is too difficult to get a good paint job when you have to worry about not getting paint on the rest of your GMC.