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Jeep Fenders: Replace Before Destruction

Posted in How To: Body Chassis on July 9, 2018
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We are big fans of preventative maintenance and prefer to replace or upgrade a part or system before it goes haywire. We call it “replace before destruction.” Replacing the factory fender flares on your Jeep is as much a part of getting larger tires as getting cool wheels to go with them. It usually happens at the same time or very soon after the bump up to bigger rubber, because if you wait too long on that “fender flare preventative maintenance,” it won’t be long before those factory flares will eventually get chewed up and spit out by those larger tires.

The choices are many, as it seems that almost everyone who makes anything for a Jeep also makes fender flares. The Poison Spyder brand has been around for quite a while, and offers top-notch products for Jeeps, among them the Crusher series of body armor that includes front and rear fender flares. We decided to take a close look at the Poison Spyder Crusher front and rear fender flares and how they are installed.

To maximize your Jeep’s wheel travel and articulation capabilities, more room must be created for uptravel. Installing a set of fenders designed to do just that, such as the Poison Spyder Crusher Flares on this JKU, can be done in your own garage if you have the right tools.

The first thing we learned was that you can order the standard-width Poison Spyder Crusher Flares with the company’s black SpyderShell finish or in bare steel. The narrow and wide styles are only available as unpainted bare steel, and you do your own thing. All three can be had in aluminum. Our subject for the installation was a Jeep Wrangler JKU, but we won’t bore you with dozens of photos of bolts being fastened–you’ll get detailed easy-to-follow and well-illustrated installation instructions. Here are the facts and figures, major installation steps, some things we learned, and a few tips to make your installation easier.

The front side marker lights were disconnected, and then with a little TLC, a 10mm socket for the factory hex-head bolts, and a push-in retainer removal tool (pictured) to pop out the plastic push-in retainers, the inner and outer factory fenders were removed. Take care to not damage the plastic push-in retainers during removal, as some will be needed later in this installation to replace the front inner fenders.
Once the front fenders and inner flares were out of the way, we used a mild foaming degreaser spray to clean the now-exposed sheetmetal that was hidden underneath the plastic factory fenders. A thorough cleaning meant a better seat for the new rubber seals and less chance of crusty corrosion problems in between the surfaces later.
Upper subframe brackets for the Poison Spyder Crusher front flares (there is a left- and right-side bracket) were prepped with kit-supplied U-nuts in each of the five holes along the edge of the brackets. Then they were installed between the outer fender sheetmetal and inner tub brace so that the five U-nuts aligned with the five corresponding holes in the outer fender. Some of the factory hex bolts will be reused for this step, so don’t toss them during fender removal. Now is also a good time to apply masking tape around the area of the Jeep where the Crusher Flares will be installed to protect the paint from tool scratches.
This view of driver-side front Crusher Flare before installation shows the sort of sturdy construction found in front and rear Poison Spyder fender flare products we installed that day. Steel DOM 1 1/2x0.120-inch tubing and 1/8- and 3/16-inch formed brackets and plate steel form the black powdercoated flares. We had our flares finished in a matte black powdercoat at Beach Cities Powder Coating in Gardena, California.
Pre-fitting the Poison Spyder Crusher Flares is a must. It not only identifies the additional mounting holes that need to be drilled for the complete installation of the flares, but it also will indicate the sections of the factory fender that need to be trimmed for maximum wheel clearance with these flares.
Upper and lower subframe brackets for the front Poison Spyder Crusher Flares were installed during the pre-fit. Some holes must be drilled at that time for additional mounting hardware to completely mount the subframe brackets.
You can leave the flares mounted during the drilling and cutting, but we felt more comfortable completely removing them for that step in the installation. The front Poison Spyder Crusher Flares were then reinstalled with the kit-supplied new rubber gaskets.
We wanted to keep the inner fenderwells, or at least as much of them as we possibly could. The detailed instructions in the kit as to where to cut the factory inners into exactly the right shape and how to reinstall them made this step a breeze. The finished installation looks great and provides all the clearance the 37x12.50 tires need.
Like with the front flares, once the factory parts had been removed, we cleaned the entire flare mounting area with a foaming degreaser before beginning any more work. A good cleaning offered the opportunity to inspect the front and rear fenders, wheelwells, and surrounding area of the Jeep for any early signs of corrosion or wear and tear.
A professional nut-sert installation tool for the rear Poison Spyder Crusher Flares would have been easier and taken less time, but we’re cheap. What you see here is the DIY nut-sert installation tool provided with the kit with a nut-sert ready to go. There are more than a dozen of these little brass nut-serts to be placed in existing or new holes in the sheetmetal to accommodate the new rear flares. Using this “manual” version of the install tool consists of inserting an attached nut-sert into a hole in the sheetmetal. Then while holding the coupler nut in the middle still with a wrench, the bolt running through the coupler to the nut-sert is tightened with another wrench, pulling the ends of the nut-sert together and deforming it around the sheetmetal, creating a secure anchor for the flare. Removing the tool was as simple as reversing direction on the bolt.
A pre-fit of the rear Poison Spyder Crusher Flares provided the locations of any additional holes to drill or enlarge in the Jeep’s rear quarter-panel sheetmetal. Remember, measure twice (we made it thrice in this instance) and drill once. Jp Pro Tip: Using a punch to mark the locations of the new holes to be made helped us in guiding the drill bit more accurately.
Two subframe brackets (rear bracket pictured) inside the fenderwell are required for proper installation of each rear Poison Spyder Crusher Flare. This is another moment for extended patience, but it is trickier than it is difficult, and involved juggling bolts and bracket in one hand and the nuts and wrench in the other hand. Some drilling is required here too.
The rear Poison Spyder Crusher Flares are not only many times more sturdy than the factory flares, but they also look better and raise the “brow” of the fender flare quite a bit to allow full articulation of the axle without fear of rubbing a tire.
PhotosView Slideshow

Front: Before and After

PhotosView Slideshow

Rear: Before and After


Poison Spyder Customs
Banning, CA 92220
4 Wheel Parts
Compton, CA 90220

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