Our aftermarket GMC fenders for 2019-2021 GMC Sierras are handcrafted right here in America to ensure the kind of quality, durability, and craftsmanship you’ve come to expect from Advanced Fiberglass Concepts. Each Sierra fiberglass fender is made specifically for your model and year and designed for a seamless transition between the factory panels and our aftermarket body panels. These Sierra prerunner fenders are a perfect match with our 2019-2021 Sierra bedsides to create a build that is ready for any terrain.
INSTALLATION INSTRUCTIONS - FENDERS
All of our products are fairly easy to install. You will need a few hand tools and a few hours of time, depending on the products you have purchased. Also, you will reuse most of your stock hardware during this installation—it is typical to have a few screws and bolts left over, however. Advanced Fiberglass Concepts LLC does recommend that a professional install for a seamless fit install these products.
Tools required for most install:
Drill and drill bits
Screw drivers (Flat head and Phillips);
120 grit sand paper (optional)
Metal Shears or Sawzall or Plasma Cutter
Step 1: Open hood and remove bolts holding the fender down under the hood, behind the doors, under the door areas, and behind the bumper.
(Note: not all trucks have bolts located in all the areas mentioned above)
Step 2: Remove plastic liner from fender, marker lights, and headlights.
Step 3: Remove steel fender by unbolting the exterior fender from the inner shell from truck once all the bolts have been removed.
Step 4: Set fiberglass fender in its place and mark the holes that need to be drilled. (Note: Most fenders have markings where to drill, but some do not)
Step 5: Drill holes out with a 3/8 drill bit—the reason for this is so you can move the fender back and forth to align the gap in the hood and door area. To get a consistent hood and door gap, use a mixing stick between door and fender.
Step 6: Reinstall fiberglass fender and begin to bolt it down-- but do not tighten all the bolts until you have the right gap. We recommend using a mixing stick to get the same gap at the door and hood area. Once you have the gaps spaced, tighten down the bolts. Do not over tighten! The fiberglass fender will make sounds like it is cracking—this is common as it is fiberglass, so do not worry.
You will need to be patient to get a good fit. You may need to sand some of the fender down so it does not stick out too far from the rest of the body. This is because fiberglass fenders are thicker than steel. If the hood sits too low or too high, you can adjust it by turning up or down the rubber height adjuster at the front of the hood located in the core support, or hood.
Please keep in mind—although all of our products are made from factory steel fenders, hoods, and bedsides, there is a difference in fit because of the thickness of the fiberglass compared to steel. Therefore, please be patient when you start this job.
Not all trucks are the same so you may need to remove the grill and lights on some models. If you need further assistance with this installation, feel free to call us—one of our techs will be more than happy to help you.
These instructions are useful for all fenders sold by Advanced Fiberglass Concepts.—therefore some of the steps may not be needed or should be slightly altered to suit your particular vehicle and product needs.
Thank you for purchasing our product(s). We hope you are satisfied with the final result.